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id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Psi (Greek)</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 85 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-85" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">85 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Psi_(letter)" title="Psi (letter) – Afrikaans" lang="af" hreflang="af" data-title="Psi (letter)" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-als mw-list-item"><a href="https://als.wikipedia.org/wiki/%CE%A8" title="Ψ – Alemannic" lang="gsw" hreflang="gsw" data-title="Ψ" data-language-autonym="Alemannisch" data-language-local-name="Alemannic" class="interlanguage-link-target"><span>Alemannisch</span></a></li><li class="interlanguage-link interwiki-ab mw-list-item"><a href="https://ab.wikipedia.org/wiki/%CE%A8" title="Ψ – Abkhazian" lang="ab" hreflang="ab" data-title="Ψ" data-language-autonym="Аԥсшәа" data-language-local-name="Abkhazian" class="interlanguage-link-target"><span>Аԥсшәа</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%A8%D8%B3%D9%8A_(%D8%AD%D8%B1%D9%81)" title="بسي (حرف) – Arabic" lang="ar" hreflang="ar" data-title="بسي (حرف)" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-arc mw-list-item"><a href="https://arc.wikipedia.org/wiki/%CE%A8" title="Ψ – Aramaic" lang="arc" hreflang="arc" data-title="Ψ" data-language-autonym="ܐܪܡܝܐ" data-language-local-name="Aramaic" class="interlanguage-link-target"><span>ܐܪܡܝܐ</span></a></li><li class="interlanguage-link interwiki-bn mw-list-item"><a href="https://bn.wikipedia.org/wiki/%E0%A6%B8%E0%A6%BE%E0%A6%87" title="সাই – Bangla" lang="bn" hreflang="bn" data-title="সাই" data-language-autonym="বাংলা" data-language-local-name="Bangla" class="interlanguage-link-target"><span>বাংলা</span></a></li><li class="interlanguage-link interwiki-zh-min-nan mw-list-item"><a href="https://zh-min-nan.wikipedia.org/wiki/%CE%A8" title="Ψ – Minnan" lang="nan" hreflang="nan" data-title="Ψ" data-language-autonym="閩南語 / Bân-lâm-gú" data-language-local-name="Minnan" class="interlanguage-link-target"><span>閩南語 / Bân-lâm-gú</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%9F%D1%81%D1%96_(%D0%BB%D1%96%D1%82%D0%B0%D1%80%D0%B0)" title="Псі (літара) – Belarusian" lang="be" hreflang="be" data-title="Псі (літара)" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-be-x-old mw-list-item"><a href="https://be-tarask.wikipedia.org/wiki/%D0%9F%D1%81%D1%96_(%D0%B3%D1%80%D1%8D%D1%86%D0%BA%D0%B0%D1%8F_%D0%BB%D1%96%D1%82%D0%B0%D1%80%D0%B0)" title="Псі (грэцкая літара) – Belarusian (Taraškievica orthography)" lang="be-tarask" hreflang="be-tarask" data-title="Псі (грэцкая літара)" data-language-autonym="Беларуская (тарашкевіца)" data-language-local-name="Belarusian (Taraškievica orthography)" class="interlanguage-link-target"><span>Беларуская (тарашкевіца)</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%9F%D1%81%D0%B8" title="Пси – Bulgarian" lang="bg" hreflang="bg" data-title="Пси" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bar mw-list-item"><a href="https://bar.wikipedia.org/wiki/Psi_(Buachstob)" title="Psi (Buachstob) – Bavarian" lang="bar" hreflang="bar" data-title="Psi (Buachstob)" data-language-autonym="Boarisch" data-language-local-name="Bavarian" class="interlanguage-link-target"><span>Boarisch</span></a></li><li class="interlanguage-link interwiki-bo mw-list-item"><a href="https://bo.wikipedia.org/wiki/%E0%BD%95%E0%BD%B2%E0%BC%8B%E0%BD%A6%E0%BD%A0%E0%BD%BA%E0%BC%8D" title="ཕི་སའེ། – Tibetan" lang="bo" hreflang="bo" data-title="ཕི་སའེ།" data-language-autonym="བོད་ཡིག" data-language-local-name="Tibetan" class="interlanguage-link-target"><span>བོད་ཡིག</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Psi_(slovo)" title="Psi (slovo) – Bosnian" lang="bs" hreflang="bs" data-title="Psi (slovo)" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-br mw-list-item"><a href="https://br.wikipedia.org/wiki/Psi_(lizherenn)" title="Psi (lizherenn) – Breton" lang="br" hreflang="br" data-title="Psi (lizherenn)" data-language-autonym="Brezhoneg" data-language-local-name="Breton" class="interlanguage-link-target"><span>Brezhoneg</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Psi" title="Psi – Catalan" lang="ca" hreflang="ca" data-title="Psi" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Ps%C3%AD" title="Psí – Czech" lang="cs" hreflang="cs" data-title="Psí" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-cy mw-list-item"><a href="https://cy.wikipedia.org/wiki/Psi_(llythyren)" title="Psi (llythyren) – Welsh" lang="cy" hreflang="cy" data-title="Psi (llythyren)" data-language-autonym="Cymraeg" data-language-local-name="Welsh" class="interlanguage-link-target"><span>Cymraeg</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Psi_(bogstav)" title="Psi (bogstav) – Danish" lang="da" hreflang="da" data-title="Psi (bogstav)" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-se mw-list-item"><a href="https://se.wikipedia.org/wiki/%CE%A8" title="Ψ – Northern Sami" lang="se" hreflang="se" data-title="Ψ" data-language-autonym="Davvisámegiella" data-language-local-name="Northern Sami" class="interlanguage-link-target"><span>Davvisámegiella</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Psi_(Buchstabe)" title="Psi (Buchstabe) – German" lang="de" hreflang="de" data-title="Psi (Buchstabe)" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Psii" title="Psii – Estonian" lang="et" hreflang="et" data-title="Psii" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-el mw-list-item"><a href="https://el.wikipedia.org/wiki/%CE%A8%CE%B9" title="Ψι – Greek" lang="el" hreflang="el" data-title="Ψι" data-language-autonym="Ελληνικά" data-language-local-name="Greek" class="interlanguage-link-target"><span>Ελληνικά</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/%CE%A8" title="Ψ – Spanish" lang="es" hreflang="es" data-title="Ψ" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eo mw-list-item"><a href="https://eo.wikipedia.org/wiki/Psio_(litero)" title="Psio (litero) – Esperanto" lang="eo" hreflang="eo" data-title="Psio (litero)" data-language-autonym="Esperanto" data-language-local-name="Esperanto" class="interlanguage-link-target"><span>Esperanto</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Psi" title="Psi – Basque" lang="eu" hreflang="eu" data-title="Psi" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D9%BE%D8%B3%DB%8C" title="پسی – Persian" lang="fa" hreflang="fa" data-title="پسی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fo mw-list-item"><a href="https://fo.wikipedia.org/wiki/Psi" title="Psi – Faroese" lang="fo" hreflang="fo" data-title="Psi" data-language-autonym="Føroyskt" data-language-local-name="Faroese" class="interlanguage-link-target"><span>Føroyskt</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/Psi_(lettre_grecque)" title="Psi (lettre grecque) – French" lang="fr" hreflang="fr" data-title="Psi (lettre grecque)" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/S%C3%AD" title="Sí – Irish" lang="ga" hreflang="ga" data-title="Sí" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gd mw-list-item"><a href="https://gd.wikipedia.org/wiki/Psi" title="Psi – Scottish Gaelic" lang="gd" hreflang="gd" data-title="Psi" data-language-autonym="Gàidhlig" data-language-local-name="Scottish Gaelic" class="interlanguage-link-target"><span>Gàidhlig</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Psi" title="Psi – Galician" lang="gl" hreflang="gl" data-title="Psi" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-hak mw-list-item"><a href="https://hak.wikipedia.org/wiki/%CE%A8" title="Ψ – Hakka Chinese" lang="hak" hreflang="hak" data-title="Ψ" data-language-autonym="客家語 / Hak-kâ-ngî" data-language-local-name="Hakka Chinese" class="interlanguage-link-target"><span>客家語 / Hak-kâ-ngî</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%CE%A8" title="Ψ – Korean" lang="ko" hreflang="ko" data-title="Ψ" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hy mw-list-item"><a href="https://hy.wikipedia.org/wiki/%D5%93%D5%BD%D5%AB_(%D5%BF%D5%A1%D5%BC)" title="Փսի (տառ) – Armenian" lang="hy" hreflang="hy" data-title="Փսի (տառ)" data-language-autonym="Հայերեն" data-language-local-name="Armenian" class="interlanguage-link-target"><span>Հայերեն</span></a></li><li class="interlanguage-link interwiki-hr mw-list-item"><a href="https://hr.wikipedia.org/wiki/Psi_(slovo)" title="Psi (slovo) – Croatian" lang="hr" hreflang="hr" data-title="Psi (slovo)" data-language-autonym="Hrvatski" data-language-local-name="Croatian" class="interlanguage-link-target"><span>Hrvatski</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Psi_(huruf_Yunani)" title="Psi (huruf Yunani) – Indonesian" lang="id" hreflang="id" data-title="Psi (huruf Yunani)" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/Ps%C3%AD" title="Psí – Icelandic" lang="is" hreflang="is" data-title="Psí" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Psi_(lettera)" title="Psi (lettera) – Italian" lang="it" hreflang="it" data-title="Psi (lettera)" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A4%D7%A1%D7%99" title="פסי – Hebrew" lang="he" hreflang="he" data-title="פסי" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-ka mw-list-item"><a href="https://ka.wikipedia.org/wiki/%E1%83%A4%E1%83%A1%E1%83%98_(%E1%83%90%E1%83%A1%E1%83%9D)" title="ფსი (ასო) – Georgian" lang="ka" hreflang="ka" data-title="ფსი (ასო)" data-language-autonym="ქართული" data-language-local-name="Georgian" class="interlanguage-link-target"><span>ქართული</span></a></li><li class="interlanguage-link interwiki-kv mw-list-item"><a href="https://kv.wikipedia.org/wiki/%D0%9F%D1%81%D0%B8" title="Пси – Komi" lang="kv" hreflang="kv" data-title="Пси" data-language-autonym="Коми" data-language-local-name="Komi" class="interlanguage-link-target"><span>Коми</span></a></li><li class="interlanguage-link interwiki-ht mw-list-item"><a href="https://ht.wikipedia.org/wiki/%CE%A8" title="Ψ – Haitian Creole" lang="ht" hreflang="ht" data-title="Ψ" data-language-autonym="Kreyòl ayisyen" data-language-local-name="Haitian Creole" class="interlanguage-link-target"><span>Kreyòl ayisyen</span></a></li><li class="interlanguage-link interwiki-ku mw-list-item"><a href="https://ku.wikipedia.org/wiki/Ps%C3%AE" title="Psî – Kurdish" lang="ku" hreflang="ku" data-title="Psî" data-language-autonym="Kurdî" data-language-local-name="Kurdish" class="interlanguage-link-target"><span>Kurdî</span></a></li><li class="interlanguage-link interwiki-la mw-list-item"><a href="https://la.wikipedia.org/wiki/Psi" title="Psi – Latin" lang="la" hreflang="la" data-title="Psi" data-language-autonym="Latina" data-language-local-name="Latin" class="interlanguage-link-target"><span>Latina</span></a></li><li class="interlanguage-link interwiki-lv mw-list-item"><a href="https://lv.wikipedia.org/wiki/Ps%C4%AB" title="Psī – Latvian" lang="lv" hreflang="lv" data-title="Psī" data-language-autonym="Latviešu" data-language-local-name="Latvian" class="interlanguage-link-target"><span>Latviešu</span></a></li><li class="interlanguage-link interwiki-lb mw-list-item"><a href="https://lb.wikipedia.org/wiki/Psi_(Buschtaf)" title="Psi (Buschtaf) – Luxembourgish" lang="lb" hreflang="lb" data-title="Psi (Buschtaf)" data-language-autonym="Lëtzebuergesch" data-language-local-name="Luxembourgish" class="interlanguage-link-target"><span>Lëtzebuergesch</span></a></li><li class="interlanguage-link interwiki-lez mw-list-item"><a href="https://lez.wikipedia.org/wiki/%D0%9F%D1%81%D0%B8_(%D0%B3%D1%8C%D0%B0%D1%80%D1%84)" title="Пси (гьарф) – Lezghian" lang="lez" hreflang="lez" data-title="Пси (гьарф)" data-language-autonym="Лезги" data-language-local-name="Lezghian" class="interlanguage-link-target"><span>Лезги</span></a></li><li class="interlanguage-link interwiki-lt mw-list-item"><a href="https://lt.wikipedia.org/wiki/Psi_(raid%C4%97)" title="Psi (raidė) – Lithuanian" lang="lt" hreflang="lt" data-title="Psi (raidė)" data-language-autonym="Lietuvių" data-language-local-name="Lithuanian" class="interlanguage-link-target"><span>Lietuvių</span></a></li><li class="interlanguage-link interwiki-hu mw-list-item"><a href="https://hu.wikipedia.org/wiki/Psz%C3%AD_(bet%C5%B1)" title="Pszí (betű) – Hungarian" lang="hu" hreflang="hu" data-title="Pszí (betű)" data-language-autonym="Magyar" data-language-local-name="Hungarian" class="interlanguage-link-target"><span>Magyar</span></a></li><li class="interlanguage-link interwiki-ml mw-list-item"><a href="https://ml.wikipedia.org/wiki/%E0%B4%B8%E0%B5%88_(%E0%B4%85%E0%B4%95%E0%B5%8D%E0%B4%B7%E0%B4%B0%E0%B4%82)" title="സൈ (അക്ഷരം) – Malayalam" lang="ml" hreflang="ml" data-title="സൈ (അക്ഷരം)" data-language-autonym="മലയാളം" data-language-local-name="Malayalam" class="interlanguage-link-target"><span>മലയാളം</span></a></li><li class="interlanguage-link interwiki-mr mw-list-item"><a href="https://mr.wikipedia.org/wiki/%E0%A4%AA%E0%A5%8D%E0%A4%B8%E0%A4%BE%E0%A4%AF_(%E0%A4%85%E0%A4%95%E0%A5%8D%E0%A4%B7%E0%A4%B0)" title="प्साय (अक्षर) – Marathi" lang="mr" hreflang="mr" data-title="प्साय (अक्षर)" data-language-autonym="मराठी" data-language-local-name="Marathi" class="interlanguage-link-target"><span>मराठी</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Psi" title="Psi – Malay" lang="ms" hreflang="ms" data-title="Psi" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-cdo mw-list-item"><a href="https://cdo.wikipedia.org/wiki/Psi_(c%C3%AA-m%C5%8D%CC%A4)" title="Psi (cê-mō̤) – Mindong" lang="cdo" hreflang="cdo" data-title="Psi (cê-mō̤)" data-language-autonym="閩東語 / Mìng-dĕ̤ng-ngṳ̄" data-language-local-name="Mindong" class="interlanguage-link-target"><span>閩東語 / Mìng-dĕ̤ng-ngṳ̄</span></a></li><li class="interlanguage-link interwiki-nah mw-list-item"><a href="https://nah.wikipedia.org/wiki/%CE%A8" title="Ψ – Nahuatl" lang="nah" hreflang="nah" data-title="Ψ" data-language-autonym="Nāhuatl" data-language-local-name="Nahuatl" class="interlanguage-link-target"><span>Nāhuatl</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Psi_(letter)" title="Psi (letter) – Dutch" lang="nl" hreflang="nl" data-title="Psi (letter)" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%CE%A8" title="Ψ – Japanese" lang="ja" hreflang="ja" data-title="Ψ" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-frr mw-list-item"><a href="https://frr.wikipedia.org/wiki/Psi_(buksteew)" title="Psi (buksteew) – Northern Frisian" lang="frr" hreflang="frr" data-title="Psi (buksteew)" data-language-autonym="Nordfriisk" data-language-local-name="Northern Frisian" class="interlanguage-link-target"><span>Nordfriisk</span></a></li><li class="interlanguage-link interwiki-no mw-list-item"><a href="https://no.wikipedia.org/wiki/Psi" title="Psi – Norwegian Bokmål" lang="nb" hreflang="nb" data-title="Psi" data-language-autonym="Norsk bokmål" data-language-local-name="Norwegian Bokmål" class="interlanguage-link-target"><span>Norsk bokmål</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Psi" title="Psi – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Psi" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-oc mw-list-item"><a href="https://oc.wikipedia.org/wiki/Psi" title="Psi – Occitan" lang="oc" hreflang="oc" data-title="Psi" data-language-autonym="Occitan" data-language-local-name="Occitan" class="interlanguage-link-target"><span>Occitan</span></a></li><li class="interlanguage-link interwiki-pa mw-list-item"><a href="https://pa.wikipedia.org/wiki/%E0%A8%B8%E0%A8%BE%E0%A8%88_(%E0%A8%85%E0%A9%B1%E0%A8%96%E0%A8%B0)" title="ਸਾਈ (ਅੱਖਰ) – Punjabi" lang="pa" hreflang="pa" data-title="ਸਾਈ (ਅੱਖਰ)" data-language-autonym="ਪੰਜਾਬੀ" data-language-local-name="Punjabi" class="interlanguage-link-target"><span>ਪੰਜਾਬੀ</span></a></li><li class="interlanguage-link interwiki-nds mw-list-item"><a href="https://nds.wikipedia.org/wiki/Psi" title="Psi – Low German" lang="nds" hreflang="nds" data-title="Psi" data-language-autonym="Plattdüütsch" data-language-local-name="Low German" class="interlanguage-link-target"><span>Plattdüütsch</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Psi_(litera)" title="Psi (litera) – Polish" lang="pl" hreflang="pl" data-title="Psi (litera)" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/%CE%A8" title="Ψ – Portuguese" lang="pt" hreflang="pt" data-title="Ψ" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Psi_(liter%C4%83)" title="Psi (literă) – Romanian" lang="ro" hreflang="ro" data-title="Psi (literă)" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%9F%D1%81%D0%B8_(%D0%B1%D1%83%D0%BA%D0%B2%D0%B0_%D0%B3%D1%80%D0%B5%D1%87%D0%B5%D1%81%D0%BA%D0%BE%D0%B3%D0%BE_%D0%B0%D0%BB%D1%84%D0%B0%D0%B2%D0%B8%D1%82%D0%B0)" title="Пси (буква греческого алфавита) – Russian" lang="ru" hreflang="ru" data-title="Пси (буква греческого алфавита)" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Psi_(letter)" title="Psi (letter) – Simple English" lang="en-simple" hreflang="en-simple" data-title="Psi (letter)" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Ps%C3%AD_(gr%C3%A9cke_p%C3%ADsmeno)" title="Psí (grécke písmeno) – Slovak" lang="sk" hreflang="sk" data-title="Psí (grécke písmeno)" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sl mw-list-item"><a href="https://sl.wikipedia.org/wiki/Psi" title="Psi – Slovenian" lang="sl" hreflang="sl" data-title="Psi" data-language-autonym="Slovenščina" data-language-local-name="Slovenian" class="interlanguage-link-target"><span>Slovenščina</span></a></li><li class="interlanguage-link interwiki-ckb mw-list-item"><a href="https://ckb.wikipedia.org/wiki/%D9%BE%D8%B3%DB%8C_(%D9%BE%DB%8C%D8%AA)" title="پسی (پیت) – Central Kurdish" lang="ckb" hreflang="ckb" data-title="پسی (پیت)" data-language-autonym="کوردی" data-language-local-name="Central Kurdish" class="interlanguage-link-target"><span>کوردی</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%9F%D1%81%D0%B8_(%D1%81%D0%BB%D0%BE%D0%B2%D0%BE)" title="Пси (слово) – Serbian" lang="sr" hreflang="sr" data-title="Пси (слово)" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" class="interlanguage-link-target"><span>Српски / srpski</span></a></li><li class="interlanguage-link interwiki-sh mw-list-item"><a href="https://sh.wikipedia.org/wiki/Psi_(slovo)" title="Psi (slovo) – Serbo-Croatian" lang="sh" hreflang="sh" data-title="Psi (slovo)" data-language-autonym="Srpskohrvatski / српскохрватски" data-language-local-name="Serbo-Croatian" class="interlanguage-link-target"><span>Srpskohrvatski / српскохрватски</span></a></li><li class="interlanguage-link interwiki-fi mw-list-item"><a href="https://fi.wikipedia.org/wiki/Psii" title="Psii – Finnish" lang="fi" hreflang="fi" data-title="Psii" data-language-autonym="Suomi" data-language-local-name="Finnish" class="interlanguage-link-target"><span>Suomi</span></a></li><li class="interlanguage-link interwiki-sv mw-list-item"><a href="https://sv.wikipedia.org/wiki/Psi" title="Psi – Swedish" lang="sv" hreflang="sv" data-title="Psi" data-language-autonym="Svenska" data-language-local-name="Swedish" class="interlanguage-link-target"><span>Svenska</span></a></li><li class="interlanguage-link interwiki-th mw-list-item"><a href="https://th.wikipedia.org/wiki/%E0%B8%9E%E0%B9%84%E0%B8%8B" title="พไซ – Thai" lang="th" hreflang="th" data-title="พไซ" data-language-autonym="ไทย" data-language-local-name="Thai" class="interlanguage-link-target"><span>ไทย</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Psi_(harf)" title="Psi (harf) – Turkish" lang="tr" hreflang="tr" data-title="Psi (harf)" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-uk mw-list-item"><a href="https://uk.wikipedia.org/wiki/%D0%9F%D1%81%D1%96_(%D0%BB%D1%96%D1%82%D0%B5%D1%80%D0%B0)" title="Псі (літера) – Ukrainian" lang="uk" hreflang="uk" data-title="Псі (літера)" data-language-autonym="Українська" data-language-local-name="Ukrainian" class="interlanguage-link-target"><span>Українська</span></a></li><li class="interlanguage-link interwiki-vep mw-list-item"><a href="https://vep.wikipedia.org/wiki/Psi" title="Psi – Veps" lang="vep" hreflang="vep" data-title="Psi" data-language-autonym="Vepsän kel’" data-language-local-name="Veps" class="interlanguage-link-target"><span>Vepsän kel’</span></a></li><li class="interlanguage-link interwiki-vi mw-list-item"><a href="https://vi.wikipedia.org/wiki/Psi" title="Psi – Vietnamese" lang="vi" hreflang="vi" data-title="Psi" data-language-autonym="Tiếng Việt" data-language-local-name="Vietnamese" class="interlanguage-link-target"><span>Tiếng Việt</span></a></li><li class="interlanguage-link interwiki-war mw-list-item"><a href="https://war.wikipedia.org/wiki/Psi_(agi)" title="Psi (agi) – Waray" lang="war" hreflang="war" data-title="Psi (agi)" data-language-autonym="Winaray" data-language-local-name="Waray" class="interlanguage-link-target"><span>Winaray</span></a></li><li class="interlanguage-link interwiki-wuu mw-list-item"><a href="https://wuu.wikipedia.org/wiki/%CE%A8" title="Ψ – Wu" lang="wuu" hreflang="wuu" data-title="Ψ" data-language-autonym="吴语" data-language-local-name="Wu" class="interlanguage-link-target"><span>吴语</span></a></li><li class="interlanguage-link interwiki-zh-yue mw-list-item"><a href="https://zh-yue.wikipedia.org/wiki/%CE%A8" title="Ψ – Cantonese" lang="yue" hreflang="yue" data-title="Ψ" data-language-autonym="粵語" data-language-local-name="Cantonese" class="interlanguage-link-target"><span>粵語</span></a></li><li class="interlanguage-link interwiki-diq mw-list-item"><a href="https://diq.wikipedia.org/wiki/%CE%A8" title="Ψ – 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//upload.wikimedia.org/wikipedia/en/thumb/1/1b/Semi-protection-shackle.svg/40px-Semi-protection-shackle.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span></div></div> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"><span class="mw-redirectedfrom">(Redirected from <a href="/w/index.php?title=Psi_(letter)&redirect=no" class="mw-redirect" title="Psi (letter)">Psi (letter)</a>)</span></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Penultimate letter in the Greek alphabet</div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">This article is about the Greek letter. For the Cyrillic letter, see <a href="/wiki/Psi_(Cyrillic)" title="Psi (Cyrillic)">Psi (Cyrillic)</a>.</div> <p class="mw-empty-elt"> </p> <style data-mw-deduplicate="TemplateStyles:r1251242444">.mw-parser-output .ambox{border:1px solid #a2a9b1;border-left:10px solid #36c;background-color:#fbfbfb;box-sizing:border-box}.mw-parser-output .ambox+link+.ambox,.mw-parser-output .ambox+link+style+.ambox,.mw-parser-output .ambox+link+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+style+.ambox,.mw-parser-output .ambox+.mw-empty-elt+link+link+.ambox{margin-top:-1px}html body.mediawiki .mw-parser-output .ambox.mbox-small-left{margin:4px 1em 4px 0;overflow:hidden;width:238px;border-collapse:collapse;font-size:88%;line-height:1.25em}.mw-parser-output .ambox-speedy{border-left:10px solid #b32424;background-color:#fee7e6}.mw-parser-output .ambox-delete{border-left:10px solid #b32424}.mw-parser-output .ambox-content{border-left:10px solid #f28500}.mw-parser-output .ambox-style{border-left:10px solid #fc3}.mw-parser-output .ambox-move{border-left:10px solid #9932cc}.mw-parser-output .ambox-protection{border-left:10px solid #a2a9b1}.mw-parser-output .ambox .mbox-text{border:none;padding:0.25em 0.5em;width:100%}.mw-parser-output .ambox .mbox-image{border:none;padding:2px 0 2px 0.5em;text-align:center}.mw-parser-output .ambox .mbox-imageright{border:none;padding:2px 0.5em 2px 0;text-align:center}.mw-parser-output .ambox .mbox-empty-cell{border:none;padding:0;width:1px}.mw-parser-output .ambox .mbox-image-div{width:52px}@media(min-width:720px){.mw-parser-output .ambox{margin:0 10%}}@media print{body.ns-0 .mw-parser-output .ambox{display:none!important}}</style><table class="box-More_citations_needed plainlinks metadata ambox ambox-content ambox-Refimprove" role="presentation"><tbody><tr><td class="mbox-image"><div class="mbox-image-div"><span typeof="mw:File"><a href="/wiki/File:Question_book-new.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/50px-Question_book-new.svg.png" decoding="async" width="50" height="39" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/75px-Question_book-new.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/99/Question_book-new.svg/100px-Question_book-new.svg.png 2x" data-file-width="512" data-file-height="399" /></a></span></div></td><td class="mbox-text"><div class="mbox-text-span">This article <b>needs additional citations for <a href="/wiki/Wikipedia:Verifiability" title="Wikipedia:Verifiability">verification</a></b>.<span class="hide-when-compact"> Please help <a href="/wiki/Special:EditPage/Psi_(Greek)" title="Special:EditPage/Psi (Greek)">improve this article</a> by <a href="/wiki/Help:Referencing_for_beginners" title="Help:Referencing for beginners">adding citations to reliable sources</a>. Unsourced material may be challenged and removed.<br /><small><span class="plainlinks"><i>Find sources:</i> <a rel="nofollow" class="external text" href="https://www.google.com/search?as_eq=wikipedia&q=%22Psi%22+Greek">"Psi" Greek</a> – <a rel="nofollow" class="external text" href="https://www.google.com/search?tbm=nws&q=%22Psi%22+Greek+-wikipedia&tbs=ar:1">news</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?&q=%22Psi%22+Greek&tbs=bkt:s&tbm=bks">newspapers</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.google.com/search?tbs=bks:1&q=%22Psi%22+Greek+-wikipedia">books</a> <b>·</b> <a rel="nofollow" class="external text" href="https://scholar.google.com/scholar?q=%22Psi%22+Greek">scholar</a> <b>·</b> <a rel="nofollow" class="external text" href="https://www.jstor.org/action/doBasicSearch?Query=%22Psi%22+Greek&acc=on&wc=on">JSTOR</a></span></small></span> <span class="date-container"><i>(<span class="date">May 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href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><table class="sidebar nomobile nowraplinks greek-alphabet-sidebar" style="width:20em"><tbody><tr><td class="sidebar-top-image"><span class="skin-invert" typeof="mw:File"><a href="/wiki/File:Psi_uc_lc.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/1/15/Psi_uc_lc.svg/100px-Psi_uc_lc.svg.png" decoding="async" width="100" height="67" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/1/15/Psi_uc_lc.svg/150px-Psi_uc_lc.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/1/15/Psi_uc_lc.svg/200px-Psi_uc_lc.svg.png 2x" data-file-width="3000" data-file-height="2000" /></a></span></td></tr><tr><th class="sidebar-title"><a href="/wiki/Greek_alphabet" title="Greek alphabet">Greek alphabet</a></th></tr><tr><td class="sidebar-content hlist"> <table style="width:100%;border-collapse:collapse;border-spacing:0px 0px;border:none;margin-left:0.7em;text-align:left;"><tbody><tr style="vertical-align:top"><td> Αα</td><td style="padding-right:1.0em;"> <a href="/wiki/Alpha" title="Alpha">Alpha</a></td><td> Νν</td><td style="padding-right:0.6em;"> <a href="/wiki/Nu_(letter)" title="Nu (letter)">Nu</a></td></tr><tr style="vertical-align:top"><td> Ββ</td><td style="padding-right:1.0em;"> <a href="/wiki/Beta" title="Beta">Beta</a></td><td> Ξξ</td><td style="padding-right:0.6em;"> <a href="/wiki/Xi_(letter)" title="Xi (letter)">Xi</a></td></tr><tr style="vertical-align:top"><td> Γγ</td><td style="padding-right:1.0em;"> <a href="/wiki/Gamma" title="Gamma">Gamma</a></td><td> Οο</td><td style="padding-right:0.6em;"> <a href="/wiki/Omicron" title="Omicron">Omicron</a></td></tr><tr style="vertical-align:top"><td> Δδ</td><td style="padding-right:1.0em;"> <a href="/wiki/Delta_(letter)" title="Delta (letter)">Delta</a></td><td> Ππ</td><td style="padding-right:0.6em;"> <a href="/wiki/Pi_(letter)" title="Pi (letter)">Pi</a></td></tr><tr style="vertical-align:top"><td> Εε</td><td style="padding-right:1.0em;"> <a href="/wiki/Epsilon" title="Epsilon">Epsilon</a></td><td> Ρρ</td><td style="padding-right:0.6em;"> <a href="/wiki/Rho" title="Rho">Rho</a></td></tr><tr style="vertical-align:top"><td> Ζζ</td><td style="padding-right:1.0em;"> <a href="/wiki/Zeta" title="Zeta">Zeta</a></td><td> Σσς</td><td style="padding-right:0.6em;"> <a href="/wiki/Sigma" title="Sigma">Sigma</a></td></tr><tr style="vertical-align:top"><td> Ηη</td><td style="padding-right:1.0em;"> <a href="/wiki/Eta" title="Eta">Eta</a></td><td> Ττ</td><td style="padding-right:0.6em;"> <a href="/wiki/Tau" title="Tau">Tau</a></td></tr><tr style="vertical-align:top"><td> Θθ</td><td style="padding-right:1.0em;"> <a href="/wiki/Theta" title="Theta">Theta</a></td><td> Υυ</td><td style="padding-right:0.6em;"> <a href="/wiki/Upsilon" title="Upsilon">Upsilon</a></td></tr><tr style="vertical-align:top"><td> Ιι</td><td style="padding-right:1.0em;"> <a href="/wiki/Iota" title="Iota">Iota</a></td><td> Φφ</td><td style="padding-right:0.6em;"> <a href="/wiki/Phi" title="Phi">Phi</a></td></tr><tr style="vertical-align:top"><td> Κκ</td><td style="padding-right:1.0em;"> <a href="/wiki/Kappa" title="Kappa">Kappa</a></td><td> Χχ</td><td style="padding-right:0.6em;"> <a href="/wiki/Chi_(letter)" title="Chi (letter)">Chi</a></td></tr><tr style="vertical-align:top"><td> Λλ</td><td style="padding-right:1.0em;"> <a href="/wiki/Lambda" title="Lambda">Lambda</a></td><td> Ψψ</td><td style="padding-right:0.6em;"> <a class="mw-selflink selflink">Psi</a></td></tr><tr style="vertical-align:top"><td> Μμ</td><td style="padding-right:1.0em;"> <a href="/wiki/Mu_(letter)" title="Mu (letter)">Mu</a></td><td> Ωω</td><td style="padding-right:0.6em;"> <a href="/wiki/Omega" title="Omega">Omega</a></td></tr></tbody></table></td> </tr><tr><th class="sidebar-heading"> <a href="/wiki/History_of_the_Greek_alphabet" title="History of the Greek alphabet">History</a></th></tr><tr><td class="sidebar-content hlist"> <div style="display:inline-block; padding:0.2em 0.4em; line-height:1.2em; line-height:1.1em;padding-bottom:0.45em;"> <a href="/wiki/Archaic_Greek_alphabets" title="Archaic Greek alphabets"><b>Archaic local variants</b></a></div> <table style="width:100%;border-collapse:collapse;border-spacing:0px 0px;border:none;margin-left:0.7em;text-align:left;"><tbody><tr style="vertical-align:top"><td> Ϝϝ</td><td style="padding-right:1.0em;"> <a href="/wiki/Digamma" title="Digamma">Digamma</a></td><td> Ͱͱ</td><td style="padding-right:0.6em;"> <a href="/wiki/Heta" title="Heta">Heta</a></td></tr><tr style="vertical-align:top"><td> Ϻϻ</td><td style="padding-right:1.0em;"> <a href="/wiki/San_(letter)" title="San (letter)">San</a></td><td> Ϙϙ</td><td style="padding-right:0.6em;"> <a href="/wiki/Koppa_(letter)" title="Koppa (letter)">Koppa</a></td></tr><tr style="vertical-align:top"><td> Ͷͷ</td><td style="padding-right:1.0em;"> <div class="hlist inline"><ul><li><a href="/wiki/Tsan" class="mw-redirect" title="Tsan">Tsan</a></li><li><a href="/wiki/Digamma#Pamphylian_digamma" title="Digamma">Digamma</a></li></ul></div></td><td> Ͳͳ</td><td style="padding-right:0.6em;"> <a href="/wiki/Sampi" title="Sampi">Sampi</a></td></tr><tr style="vertical-align:top"><td>Ϸϸ</td><td style="padding-right:1.0em;"> <a href="/wiki/Sho_(letter)" title="Sho (letter)">Sho</a></td><td></td><td style="padding-right:0.6em;"></td></tr></tbody></table></td> </tr><tr><th class="sidebar-heading"> Diacritics and other symbols</th></tr><tr><td class="sidebar-content hlist"> <div style="display:inline-block; padding:0.2em 0.4em; line-height:1.2em; padding-top:0.3em;line-height:1.1em;padding-bottom:0;"><a href="/wiki/Greek_diacritics" title="Greek diacritics">Diacritics</a></div> <div class="hlist"><ul><li><a href="/wiki/Acute_accent" title="Acute accent">ά</a></li><li><a href="/wiki/Grave_accent" title="Grave accent">ὰ</a></li><li><a href="/wiki/Circumflex" title="Circumflex">ᾶ</a></li><li><a href="/wiki/Smooth_breathing" title="Smooth breathing">ἀ</a></li><li><a href="/wiki/Rough_breathing" title="Rough breathing">ἁ</a></li><li><a href="/wiki/Macron_(diacritic)" title="Macron (diacritic)">ᾱ</a></li><li><a href="/wiki/Breve" title="Breve">ᾰ</a></li><li><a href="/wiki/Diaeresis_(diacritic)" title="Diaeresis (diacritic)">ϊ</a></li><li><a href="/wiki/Iota_subscript" title="Iota subscript">ᾳ</a></li><li><a href="/wiki/Caron" title="Caron">σ̌</a></li></ul></div> <div style="display:inline-block; padding:0.2em 0.4em; line-height:1.2em; padding-top:0.3em;line-height:1.1em;padding-bottom:0;"><a href="/wiki/Greek_ligatures" title="Greek ligatures">Ligatures</a></div> <div class="hlist"><ul><li style="font-size:110%;"><a href="/wiki/Ou_(ligature)" title="Ou (ligature)">ȢȢ</a></li><li style="font-size:110%;"><a href="/wiki/Kai_(conjunction)" title="Kai (conjunction)">Ϗϗ</a></li><li style="font-size:110%;"><a href="/wiki/Stigma_(ligature)" title="Stigma (ligature)">Ϛϛ</a></li><li style="font-size:110%;"><a href="/wiki/Staurogram" title="Staurogram">⳨</a></li><li style="font-size:110%;"><a href="/wiki/Chi_Rho" title="Chi Rho">☧</a></li></ul></div> <div style="display:inline-block; padding:0.2em 0.4em; line-height:1.2em; padding-top:0.3em;line-height:1.1em;padding-bottom:0;"> <a href="/wiki/Greek_numerals" title="Greek numerals">Numerals</a> (<a href="/wiki/Attic_numerals" title="Attic numerals">Attic</a>)</div> <div class="hlist"><ul><li style="font-size:110%;"><a href="/wiki/Digamma" title="Digamma">ϛ <span style="font-size:85%;">(6)</span></a></li><li style="font-size:110%;"><a href="/wiki/Koppa_(letter)" title="Koppa (letter)">ϟ <span style="font-size:85%;">(90)</span></a></li><li style="font-size:110%;"><a href="/wiki/Sampi" title="Sampi">ϡ <span style="font-size:85%;">(900)</span></a></li></ul></div></td> </tr><tr><th class="sidebar-heading"> Related topics</th></tr><tr><td class="sidebar-content hlist"> <ul><li><a href="/wiki/Greek_letters_used_in_mathematics,_science,_and_engineering" title="Greek letters used in mathematics, science, and engineering">Use as scientific symbols</a></li> <li><a href="/wiki/Greek_orthography" title="Greek orthography">Orthography</a></li> <li><a href="/wiki/Romanization_of_Greek" title="Romanization of Greek">Romanization</a></li> <li><a href="/wiki/Cyrillization_of_Greek" title="Cyrillization of Greek">Cyrillization</a></li></ul></td> </tr><tr><td class="sidebar-below plainlist"> <div class="hlist"> <ul><li><span class="noviewer" 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navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Greek_alphabet_sidebar" title="Template:Greek alphabet sidebar"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Greek_alphabet_sidebar" title="Template talk:Greek alphabet sidebar"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Greek_alphabet_sidebar" title="Special:EditPage/Template:Greek alphabet sidebar"><abbr title="Edit this template">e</abbr></a></li></ul></div></td></tr></tbody></table> <figure class="mw-default-size" typeof="mw:File/Thumb"><a href="/wiki/File:NAMA_Alphabet_grec.jpg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/d/df/NAMA_Alphabet_grec.jpg/220px-NAMA_Alphabet_grec.jpg" decoding="async" width="220" height="192" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/df/NAMA_Alphabet_grec.jpg/330px-NAMA_Alphabet_grec.jpg 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/df/NAMA_Alphabet_grec.jpg/440px-NAMA_Alphabet_grec.jpg 2x" data-file-width="1600" data-file-height="1398" /></a><figcaption>The Greek alphabet on a <a href="/wiki/Black-figure_pottery" title="Black-figure pottery">black-figure pottery</a> vessel, with an archaic chickenfoot-shaped psi.</figcaption></figure> <p><b>Psi</b> <span class="rt-commentedText nowrap"><span class="IPA nopopups noexcerpt" lang="en-fonipa"><a href="/wiki/Help:IPA/English" title="Help:IPA/English">/<span style="border-bottom:1px dotted"><span title="/ˈ/: primary stress follows">ˈ</span></span>(<span style="border-bottom:1px dotted"><span title="'p' in 'pie'">p</span></span>)<span style="border-bottom:1px dotted"><span title="'s' in 'sigh'">s</span><span title="/aɪ/: 'i' in 'tide'">aɪ</span></span>,<span class="wrap"> </span><span style="border-bottom:1px dotted"><span title="/ˈ/: primary stress follows">ˈ</span></span>(<span style="border-bottom:1px dotted"><span title="'p' in 'pie'">p</span></span>)<span style="border-bottom:1px dotted"><span title="'s' in 'sigh'">s</span><span title="/iː/: 'ee' in 'fleece'">iː</span></span>/</a></span></span> <a href="/wiki/Help:Pronunciation_respelling_key" title="Help:Pronunciation respelling key"><i title="English pronunciation respelling"><span style="font-size:90%">(P)SY</span>, <span style="font-size:90%">(P)SEE</span></i></a><sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> (uppercase <b><span title="Greek-language text"><span lang="el">Ψ</span></span></b>, lowercase <b><span title="Greek-language text"><span lang="el">ψ</span></span></b> or <b><span title="Greek-language text"><i lang="el">𝛙</i></span></b>; <a href="/wiki/Greek_language" title="Greek language">Greek</a>: <span lang="el">ψι</span> <i>psi</i> <span class="IPA nowrap" lang="el-Latn-fonipa"><a href="/wiki/Help:IPA/Greek" title="Help:IPA/Greek">[ˈpsi]</a></span>) is the twenty-third and penultimate letter of the <a href="/wiki/Greek_alphabet" title="Greek alphabet">Greek alphabet</a> and is associated with a <a href="/wiki/Greek_numerals" title="Greek numerals">numeric</a> value of 700. In both <a href="/wiki/Classical_Greek" class="mw-redirect" title="Classical Greek">Classical</a> and <a href="/wiki/Modern_Greek" title="Modern Greek">Modern Greek</a>, the letter indicates the combination <span class="IPA nowrap" lang="und-Latn-fonipa" title="Representation in the International Phonetic Alphabet (IPA)">/ps/</span> (as in English word "<a href="https://en.wiktionary.org/wiki/lapse" class="extiw" title="wikt:lapse">lapse</a>"). </p><p>For Greek loanwords in Latin and modern languages with Latin alphabets, psi is usually transliterated as "ps". </p><p>The letter's origin is uncertain. It may or may not derive from the <a href="/wiki/Phoenician_alphabet" title="Phoenician alphabet">Phoenician alphabet</a>. It appears in the 7th century BC, expressing <span class="IPA nowrap" lang="und-Latn-fonipa" title="Representation in the International Phonetic Alphabet (IPA)">/ps/</span> in the Eastern alphabets, but <span class="IPA nowrap" lang="und-Latn-fonipa" title="Representation in the International Phonetic Alphabet (IPA)">/kʰ/</span> in the <a href="/wiki/Western_Greek_alphabet" class="mw-redirect" title="Western Greek alphabet">Western alphabets</a> (the sound expressed by <a href="/wiki/%CE%A7" class="mw-redirect" title="Χ">Χ</a> in the Eastern alphabets). In writing, the early letter appears in an angular shape (<span style="background-color: white;"><span typeof="mw:File"><a href="/wiki/File:Greek_Psi_straight.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Greek_Psi_straight.svg/15px-Greek_Psi_straight.svg.png" decoding="async" width="15" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Greek_Psi_straight.svg/23px-Greek_Psi_straight.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/4d/Greek_Psi_straight.svg/30px-Greek_Psi_straight.svg.png 2x" data-file-width="43" data-file-height="53" /></a></span></span>). There were early graphical variants that omitted the stem ("chickenfoot-shaped psi" as: <span style="background-color: white;"><span typeof="mw:File"><a href="/wiki/File:Greek_Psi_V-shaped.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/62/Greek_Psi_V-shaped.svg/15px-Greek_Psi_V-shaped.svg.png" decoding="async" width="15" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/62/Greek_Psi_V-shaped.svg/23px-Greek_Psi_V-shaped.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/62/Greek_Psi_V-shaped.svg/30px-Greek_Psi_V-shaped.svg.png 2x" data-file-width="43" data-file-height="53" /></a></span></span> or <span style="background-color: white;"><span typeof="mw:File"><a href="/wiki/File:Greek_Chi_05.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Greek_Chi_05.svg/15px-Greek_Chi_05.svg.png" decoding="async" width="15" height="18" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/48/Greek_Chi_05.svg/23px-Greek_Chi_05.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/48/Greek_Chi_05.svg/30px-Greek_Chi_05.svg.png 2x" data-file-width="43" data-file-height="53" /></a></span></span>).<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2024)">citation needed</span></a></i>]</sup> </p><p>The Western letter (expressing <span class="IPA nowrap" lang="und-Latn-fonipa" title="Representation in the International Phonetic Alphabet (IPA)">/kʰ/</span>, later <span class="IPA nowrap" lang="und-Latn-fonipa" title="Representation in the International Phonetic Alphabet (IPA)">/x/</span>) was adopted into the <a href="/wiki/Old_Italic_alphabets" class="mw-redirect" title="Old Italic alphabets">Old Italic alphabets</a>, and its shape is also continued into the <a href="/wiki/Algiz" title="Algiz">Algiz</a> rune <ᛉ> of the <a href="/wiki/Elder_Futhark" title="Elder Futhark">Elder Futhark</a>. </p><p>Psi, or its Arcadian variant <span style="background-color: white;"><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Greek_Psi_01.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/8/86/Greek_Psi_01.svg/13px-Greek_Psi_01.svg.png" decoding="async" width="13" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/8/86/Greek_Psi_01.svg/19px-Greek_Psi_01.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/8/86/Greek_Psi_01.svg/26px-Greek_Psi_01.svg.png 2x" data-file-width="43" data-file-height="53" /></a></span></span> or <span style="background-color: white;"><span class="mw-default-size" typeof="mw:File"><a href="/wiki/File:Greek_Psi_X-shaped.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Greek_Psi_X-shaped.svg/13px-Greek_Psi_X-shaped.svg.png" decoding="async" width="13" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Greek_Psi_X-shaped.svg/19px-Greek_Psi_X-shaped.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/9f/Greek_Psi_X-shaped.svg/26px-Greek_Psi_X-shaped.svg.png 2x" data-file-width="43" data-file-height="53" /></a></span></span> was adopted in the Latin alphabet in the form of "Antisigma" (Ↄ, ↃC, or 𐌟) during the reign of <a href="/wiki/Emperor_Claudius" class="mw-redirect" title="Emperor Claudius">Emperor Claudius</a> as one of the three <a href="/wiki/Claudian_letters" title="Claudian letters">Claudian letters</a>.<sup id="cite_ref-oliver_2-0" class="reference"><a href="#cite_note-oliver-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup> However, it was abandoned after his death.<sup class="noprint Inline-Template Template-Fact" style="white-space:nowrap;">[<i><a href="/wiki/Wikipedia:Citation_needed" title="Wikipedia:Citation needed"><span title="This claim needs references to reliable sources. (June 2024)">citation needed</span></a></i>]</sup> </p><p>The classical Greek letter was adopted into the <a href="/wiki/Early_Cyrillic_alphabet" title="Early Cyrillic alphabet">early Cyrillic alphabet</a> as "<a href="/wiki/Psi_(Cyrillic)" title="Psi (Cyrillic)">Ѱ</a>". </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Use_as_a_symbol">Use as a symbol</h2></div> <p>The letter psi is commonly used in <a href="/wiki/Physics" title="Physics">physics</a> to represent <a href="/wiki/Wave_function" title="Wave function">wave functions</a> in <a href="/wiki/Quantum_mechanics" title="Quantum mechanics">quantum mechanics</a>, such as in the <a href="/wiki/Schr%C3%B6dinger_equation" title="Schrödinger equation">Schrödinger equation</a> and <a href="/wiki/Bra%E2%80%93ket_notation" title="Bra–ket notation">bra–ket notation</a>: <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \langle \phi |\psi \rangle }"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mo fence="false" stretchy="false">⟨</mo> <mi>ϕ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo stretchy="false">|</mo> </mrow> <mi>ψ</mi> <mo fence="false" stretchy="false">⟩</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \langle \phi |\psi \rangle }</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/7d9869dca1c0dd01660954d2214ed16ca6115faf" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:5.355ex; height:2.843ex;" alt="{\displaystyle \langle \phi |\psi \rangle }"></span>. It is also used to represent the (generalized) positional states of a <a href="/wiki/Qubit" title="Qubit">qubit</a> in a <a href="/wiki/Quantum_computer" class="mw-redirect" title="Quantum computer">quantum computer</a>. </p><p>Psi is also used as the symbol for the <a href="/wiki/Polygamma_function" title="Polygamma function">polygamma function</a>, defined by </p> <dl><dd><span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi ^{(m)}(z)={\frac {d^{m}}{dz^{m}}}{\frac {\Gamma '(z)}{\Gamma (z)}}}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msup> <mi>ψ</mi> <mrow class="MJX-TeXAtom-ORD"> <mo stretchy="false">(</mo> <mi>m</mi> <mo stretchy="false">)</mo> </mrow> </msup> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> <mo>=</mo> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <msup> <mi>d</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> </mrow> </msup> <mrow> <mi>d</mi> <msup> <mi>z</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>m</mi> </mrow> </msup> </mrow> </mfrac> </mrow> <mrow class="MJX-TeXAtom-ORD"> <mfrac> <mrow> <msup> <mi mathvariant="normal">Γ</mi> <mo>′</mo> </msup> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </mrow> <mrow> <mi mathvariant="normal">Γ</mi> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </mrow> </mfrac> </mrow> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi ^{(m)}(z)={\frac {d^{m}}{dz^{m}}}{\frac {\Gamma '(z)}{\Gamma (z)}}}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/1decc04e85e32475f823041cd37367c7133f0b1b" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -2.671ex; width:21.152ex; height:6.509ex;" alt="{\displaystyle \psi ^{(m)}(z)={\frac {d^{m}}{dz^{m}}}{\frac {\Gamma '(z)}{\Gamma (z)}}}"></span></dd></dl> <p>where <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \Gamma (z)}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi mathvariant="normal">Γ</mi> <mo stretchy="false">(</mo> <mi>z</mi> <mo stretchy="false">)</mo> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \Gamma (z)}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/11ca17f880240539116aac7e6326909299e2a080" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; width:4.35ex; height:2.843ex;" alt="{\displaystyle \Gamma (z)}"></span> is the <a href="/wiki/Gamma_function" title="Gamma function">gamma function</a>.<sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup> </p><p>The letters Ψ or ψ can also be a symbol for: </p> <ul><li><a href="/wiki/Psychology" title="Psychology">Psychology</a>, <a href="/wiki/Psychiatry" title="Psychiatry">psychiatry</a>, and sometimes <a href="/wiki/Parapsychology" title="Parapsychology">parapsychology</a><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> (involving <a href="/wiki/Paranormal" title="Paranormal">paranormal</a> or relating with the <a href="/wiki/Supernatural" title="Supernatural">supernatural</a> subjects, especially research into extrasensory perception).</li> <li>In mathematics, the <a href="/wiki/Reciprocal_Fibonacci_constant" title="Reciprocal Fibonacci constant">reciprocal Fibonacci constant</a>,<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> the <a href="/wiki/Division_polynomials" title="Division polynomials">division polynomials</a>, and the <a href="/wiki/Supergolden_ratio" title="Supergolden ratio">supergolden ratio</a>.</li> <li>In mathematics, the second <a href="/wiki/Chebyshev_function" title="Chebyshev function">Chebyshev function</a><sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Water_potential" title="Water potential">Water potential</a> in movement of water between plant cells.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup></li> <li>In <a href="/wiki/Biochemistry" title="Biochemistry">biochemistry</a>, it denotes <a href="/wiki/Pseudouridine" title="Pseudouridine">pseudouridine</a>, an uncommon <a href="/wiki/Nucleoside" title="Nucleoside">nucleoside</a>.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Stream_function" title="Stream function">Stream function</a> in <a href="/wiki/Fluid_mechanics" title="Fluid mechanics">fluid mechanics</a> defining the curve to which the <a href="/wiki/Flow_velocity" title="Flow velocity">flow velocity</a> is always <a href="/wiki/Tangent" title="Tangent">tangent</a>.</li> <li>One of the <a href="/wiki/Dihedral_angle" title="Dihedral angle">dihedral angles</a> in the backbones of <a href="/wiki/Proteins" class="mw-redirect" title="Proteins">proteins</a>.<sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Indiana_University" title="Indiana University">Indiana University</a> (as a superimposed <a href="/wiki/I" title="I">I</a> and <a href="/wiki/U" title="U">U</a>).<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup></li> <li>A <a href="/wiki/Sai_(weapon)" title="Sai (weapon)">sai</a>, the name of which is pronounced the same way in English.</li> <li><a href="/wiki/Pharmacology" title="Pharmacology">Pharmacology</a>, general <a href="/wiki/Pharmacy" title="Pharmacy">pharmacy</a>.</li> <li>In <a href="/wiki/Virology" title="Virology">virology</a> the ψ site is a viral packaging signal.<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup></li> <li>The <a href="/wiki/J/%CF%88" class="mw-redirect" title="J/ψ">J/ψ</a> meson, in <a href="/wiki/Particle_physics" title="Particle physics">particle physics</a>.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup></li> <li>In the <a href="/wiki/Computability_theory" title="Computability theory">computability theory</a>, <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle \psi _{P}(x)\,\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <msub> <mi>ψ</mi> <mrow class="MJX-TeXAtom-ORD"> <mi>P</mi> </mrow> </msub> <mo stretchy="false">(</mo> <mi>x</mi> <mo stretchy="false">)</mo> <mspace width="thinmathspace" /> <mspace width="negativethinmathspace" /> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle \psi _{P}(x)\,\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0b3ac9acfee19a305644fff4cb3e828d531e6c76" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.838ex; margin-right: -0.387ex; width:6.506ex; height:2.843ex;" alt="{\displaystyle \psi _{P}(x)\,\!}"></span> represents the return value <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle Y\,\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>Y</mi> <mspace width="thinmathspace" /> <mspace width="negativethinmathspace" /> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle Y\,\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/82e65066132416db15d76f148ea4436daf49c863" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.171ex; margin-right: -0.387ex; width:2.16ex; height:2.009ex;" alt="{\displaystyle Y\,\!}"></span> of a program <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle P\,\!}"> <semantics> <mrow class="MJX-TeXAtom-ORD"> <mstyle displaystyle="true" scriptlevel="0"> <mi>P</mi> <mspace width="thinmathspace" /> <mspace width="negativethinmathspace" /> </mstyle> </mrow> <annotation encoding="application/x-tex">{\displaystyle P\,\!}</annotation> </semantics> </math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/7c3e0ad16487ef34cb49cae8db35e4333ec4d491" class="mwe-math-fallback-image-inline mw-invert skin-invert" aria-hidden="true" style="vertical-align: -0.338ex; margin-right: -0.387ex; width:2.133ex; height:2.176ex;" alt="{\displaystyle P\,\!}"></span>.</li> <li>In <a href="/wiki/Circadian_physiology" class="mw-redirect" title="Circadian physiology">circadian physiology</a>, ψ represents the phase relationship between a <a href="/wiki/Zeitgeber" title="Zeitgeber">zeitgeber</a> and a <a href="/wiki/Biological_rhythm" title="Biological rhythm">biological rhythm</a>.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup></li> <li>In <a href="/wiki/Building" title="Building">building</a>, to represent an adjustment to a <a href="/wiki/U-value" class="mw-redirect" title="U-value">U-value</a>, accounting for <a href="/wiki/Thermal_bridge" title="Thermal bridge">thermal bridge</a> effects.</li> <li>The <a href="/wiki/Ordinal_collapsing_function" title="Ordinal collapsing function">ordinal collapsing function</a> and <a href="/wiki/Ordinal_notation" title="Ordinal notation">notation</a> developed by Wilfried Buchholz.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup></li> <li>In <a href="/wiki/Biblical_studies" title="Biblical studies">Biblical studies</a>, as an abbreviation for the book of <a href="/wiki/Psalms" title="Psalms">Psalms</a>.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup></li></ul> <div class="mw-heading mw-heading2"><h2 id="Unicode">Unicode</h2></div> <ul><li><span class="nowrap"><style data-mw-deduplicate="TemplateStyles:r886049734">.mw-parser-output .monospaced{font-family:monospace,monospace}</style><span class="monospaced">U+03A8</span> </span><span style="font-size:125%;line-height:1em">Ψ</span> <span style="font-variant: small-caps; text-transform: lowercase;">GREEK CAPITAL LETTER PSI</span> (<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">&Psi;</span>)<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+03C8</span> </span><span style="font-size:125%;line-height:1em">ψ</span> <span style="font-variant: small-caps; text-transform: lowercase;">GREEK SMALL LETTER PSI</span> (<link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">&psi;</span>)</li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+0470</span> </span><span style="font-size:125%;line-height:1em">Ѱ</span> <span style="font-variant: small-caps; text-transform: lowercase;">CYRILLIC CAPITAL LETTER PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+0471</span> </span><span style="font-size:125%;line-height:1em">ѱ</span> <span style="font-variant: small-caps; text-transform: lowercase;">CYRILLIC SMALL LETTER PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D2A</span> </span><span style="font-size:125%;line-height:1em">ᴪ</span> <span style="font-variant: small-caps; text-transform: lowercase;">GREEK LETTER SMALL CAPITAL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+2CAE</span> </span><span style="font-size:125%;line-height:1em">Ⲯ</span> <span style="font-variant: small-caps; text-transform: lowercase;">COPTIC CAPITAL LETTER PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+2CAF</span> </span><span style="font-size:125%;line-height:1em">ⲯ</span> <span style="font-variant: small-caps; text-transform: lowercase;">COPTIC SMALL LETTER PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D6BF</span> </span><span style="font-size:125%;line-height:1em">𝚿</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL BOLD CAPITAL PSI</span><sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>a<span class="cite-bracket">]</span></a></sup></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D6D9</span> </span><span style="font-size:125%;line-height:1em">𝛙</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL BOLD SMALL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D6F9</span> </span><span style="font-size:125%;line-height:1em">𝛹</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL ITALIC CAPITAL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D713</span> </span><span style="font-size:125%;line-height:1em">𝜓</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL ITALIC SMALL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D733</span> </span><span style="font-size:125%;line-height:1em">𝜳</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL BOLD ITALIC CAPITAL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D74D</span> </span><span style="font-size:125%;line-height:1em">𝝍</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL BOLD ITALIC SMALL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D76D</span> </span><span style="font-size:125%;line-height:1em">𝝭</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL SANS-SERIF BOLD CAPITAL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D787</span> </span><span style="font-size:125%;line-height:1em">𝞇</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL SANS-SERIF BOLD SMALL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D7A7</span> </span><span style="font-size:125%;line-height:1em">𝞧</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL SANS-SERIF BOLD ITALIC CAPITAL PSI</span></li> <li><span class="nowrap"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r886049734"><span class="monospaced">U+1D7C1</span> </span><span style="font-size:125%;line-height:1em">𝟁</span> <span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL SANS-SERIF BOLD ITALIC SMALL PSI</span></li></ul> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist reflist-lower-alpha"> <div class="mw-references-wrap"><ol class="references"> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text">The <span class="smallcaps"><span style="font-variant: small-caps; text-transform: lowercase;">MATHEMATICAL</span></span> characters are used in math. Stylized Greek text should be encoded using the normal Greek letters, with markup and formatting to indicate text style.</span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:Wiktionary-logo-en-v2.svg" class="mw-file-description"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/40px-Wiktionary-logo-en-v2.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/60px-Wiktionary-logo-en-v2.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/9/99/Wiktionary-logo-en-v2.svg/80px-Wiktionary-logo-en-v2.svg.png 2x" data-file-width="512" data-file-height="512" /></a></span></div> <div class="side-box-text plainlist">Look up <i><b><a href="https://en.wiktionary.org/wiki/%CE%A8" class="extiw" title="wiktionary:Ψ">Ψ</a></b></i> or <i><b><a href="https://en.wiktionary.org/wiki/%CF%88" class="extiw" title="wiktionary:ψ">ψ</a></b></i> in Wiktionary, the free dictionary.</div></div> </div> <ul><li><a href="/wiki/Psi_and_phi_type_figurine" title="Psi and phi type figurine">Psi and phi type figurine</a></li> <li><a href="/wiki/Psi_(Cyrillic)" title="Psi (Cyrillic)">Psi (Cyrillic)</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="Notes_and_references">Notes and references</h2></div> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite class="citation book cs1">"psi". <i>The Chambers Dictionary</i> (9th ed.). Chambers. 2003. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-550-10105-5" title="Special:BookSources/0-550-10105-5"><bdi>0-550-10105-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=bookitem&rft.atitle=psi&rft.btitle=The+Chambers+Dictionary&rft.edition=9th&rft.pub=Chambers&rft.date=2003&rft.isbn=0-550-10105-5&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-oliver-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-oliver_2-0">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFOliver1949" class="citation journal cs1">Oliver, Revilo P. (1949). "The Claudian Letter Ⱶ". <i>American Journal of Archaeology</i>. <b>53</b> (3): <span class="nowrap">249–</span>257. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.2307%2F500662">10.2307/500662</a>. <a href="/wiki/JSTOR_(identifier)" class="mw-redirect" title="JSTOR (identifier)">JSTOR</a> <a rel="nofollow" class="external text" href="https://www.jstor.org/stable/500662">500662</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:193082268">193082268</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=American+Journal+of+Archaeology&rft.atitle=The+Claudian+Letter+%E2%B1%B5&rft.volume=53&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E249-%3C%2Fspan%3E257&rft.date=1949&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A193082268%23id-name%3DS2CID&rft_id=https%3A%2F%2Fwww.jstor.org%2Fstable%2F500662%23id-name%3DJSTOR&rft_id=info%3Adoi%2F10.2307%2F500662&rft.aulast=Oliver&rft.aufirst=Revilo+P.&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWeisstein" class="citation web cs1">Weisstein, Eric W. <a rel="nofollow" class="external text" href="https://mathworld.wolfram.com/PolygammaFunction.html">"Polygamma Function"</a>. <i>mathworld.wolfram.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-08</span></span>. <q>A special function mostly commonly denoted ψ_n(z), ψ^((n))(z), or F_n(z-1)...</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=mathworld.wolfram.com&rft.atitle=Polygamma+Function&rft.aulast=Weisstein&rft.aufirst=Eric+W.&rft_id=https%3A%2F%2Fmathworld.wolfram.com%2FPolygammaFunction.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.parapsych.org/base/about.aspx">"About - The Parapsychological Association"</a>. <i>www.parapsych.org</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-09</span></span>. <q>The Parapsychological Association, Inc. (PA) is the international professional organization of scientists and scholars engaged in the study of 'psi' (or 'psychic') experiences, such as telepathy, clairvoyance, remote viewing, psychokinesis, psychic healing, and precognition.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.parapsych.org&rft.atitle=About+-+The+Parapsychological+Association&rft_id=https%3A%2F%2Fwww.parapsych.org%2Fbase%2Fabout.aspx&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWeisstein" class="citation web cs1">Weisstein, Eric W. <a rel="nofollow" class="external text" href="https://mathworld.wolfram.com/ReciprocalFibonacciConstant.html">"Reciprocal Fibonacci Constant"</a>. <i>mathworld.wolfram.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=mathworld.wolfram.com&rft.atitle=Reciprocal+Fibonacci+Constant&rft.aulast=Weisstein&rft.aufirst=Eric+W.&rft_id=https%3A%2F%2Fmathworld.wolfram.com%2FReciprocalFibonacciConstant.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWeisstein" class="citation web cs1">Weisstein, Eric W. <a rel="nofollow" class="external text" href="https://mathworld.wolfram.com/ChebyshevFunctions.html">"Chebyshev Functions"</a>. <i>mathworld.wolfram.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-01</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=mathworld.wolfram.com&rft.atitle=Chebyshev+Functions&rft.aulast=Weisstein&rft.aufirst=Eric+W.&rft_id=https%3A%2F%2Fmathworld.wolfram.com%2FChebyshevFunctions.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFWELBAUMBRADFORD1991" class="citation journal cs1">WELBAUM, GREGORY E.; BRADFORD, KENT J. (1991-03-01). <a rel="nofollow" class="external text" href="https://academic.oup.com/jxb/article-abstract/42/3/393/495356?redirectedFrom=fulltext">"Water Relations of Seed Development and Germination in Muskmelon (Cucumis melo L.): VI. INFLUENCE OF PRIMING ON GERMINATION RESPONSES TO TEMPERATURE AND WATER POTENTIAL DURING SEED DEVELOPMENT"</a>. <i>Journal of Experimental Botany</i>. <b>42</b> (3): <span class="nowrap">393–</span>399. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1093%2Fjxb%2F42.3.393">10.1093/jxb/42.3.393</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/0022-0957">0022-0957</a>. <q>Germination sensitivities to temperature and water potential (ψ) were quantified as indicators of the influence of seed maturity and priming on seed vigour.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Experimental+Botany&rft.atitle=Water+Relations+of+Seed+Development+and+Germination+in+Muskmelon+%28Cucumis+melo+L.%29%3A+VI.+INFLUENCE+OF+PRIMING+ON+GERMINATION+RESPONSES+TO+TEMPERATURE+AND+WATER+POTENTIAL+DURING+SEED+DEVELOPMENT&rft.volume=42&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E393-%3C%2Fspan%3E399&rft.date=1991-03-01&rft_id=info%3Adoi%2F10.1093%2Fjxb%2F42.3.393&rft.issn=0022-0957&rft.aulast=WELBAUM&rft.aufirst=GREGORY+E.&rft.au=BRADFORD%2C+KENT+J.&rft_id=https%3A%2F%2Facademic.oup.com%2Fjxb%2Farticle-abstract%2F42%2F3%2F393%2F495356%3FredirectedFrom%3Dfulltext&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFIUPAC-IUB_Commission_on_Biochemical_Nomenclature1970" class="citation journal cs1">IUPAC-IUB Commission on Biochemical Nomenclature (1970). "Abbreviations and symbols for nucleic acids, polynucleotides, and their constituents". <i><a href="/wiki/Biochemistry_(journal)" title="Biochemistry (journal)">Biochemistry</a></i>. <b>9</b> (20): <span class="nowrap">4022–</span>4027. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1021%2Fbi00822a023">10.1021/bi00822a023</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Biochemistry&rft.atitle=Abbreviations+and+symbols+for+nucleic+acids%2C+polynucleotides%2C+and+their+constituents&rft.volume=9&rft.issue=20&rft.pages=%3Cspan+class%3D%22nowrap%22%3E4022-%3C%2Fspan%3E4027&rft.date=1970&rft_id=info%3Adoi%2F10.1021%2Fbi00822a023&rft.au=IUPAC-IUB+Commission+on+Biochemical+Nomenclature&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://proteinstructures.com/structure/ramachandran-plot/">"Torsion Angles and the Ramachnadran Plot in Protein Structures"</a>. <i>proteinstructures.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-09</span></span>. <q>These angles describe the rotations of the polypeptide backbone around the bonds between N-Cα (called Phi, φ) and Cα-C (called Psi, ψ) and essentially determine the fold of the protein.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=proteinstructures.com&rft.atitle=Torsion+Angles+and+the+Ramachnadran+Plot+in+Protein+Structures&rft_id=https%3A%2F%2Fproteinstructures.com%2Fstructure%2Framachandran-plot%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text">Although the university itself refers to its logo as a <a href="/wiki/Trident" title="Trident">trident</a>, not the Greek letter psi: <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://brand.iu.edu/design/logos-lockups/index.html">"The IU trident—the only logo at Indiana University"</a>. Indiana University<span class="reference-accessdate">. Retrieved <span class="nowrap">2020-07-31</span></span>. <q>At IU, the trident is the only logo we use, both institution-wide and at the unit level.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=The+IU+trident%E2%80%94the+only+logo+at+Indiana+University&rft.pub=Indiana+University&rft_id=https%3A%2F%2Fbrand.iu.edu%2Fdesign%2Flogos-lockups%2Findex.html&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFRein2020" class="citation journal cs1">Rein, Alan (2020-07-28). <a rel="nofollow" class="external text" href="http://web.archive.org/web/20250103000531/https://pmc.ncbi.nlm.nih.gov/articles/PMC7443930/">"The heart of the HIV RNA packaging signal?"</a>. <i>Proceedings of the National Academy of Sciences of the United States of America</i>. <b>117</b> (33). <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1073%2Fpna">10.1073/pna</a>. Archived from <a rel="nofollow" class="external text" href="https://pmc.ncbi.nlm.nih.gov/articles/PMC7443930/">the original</a> on 2025-01-03. <q>vRNA is selectively packaged because it contains a "packaging signal" or "ψ" [also designated the "core encapsidation signal" (2)].</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Proceedings+of+the+National+Academy+of+Sciences+of+the+United+States+of+America&rft.atitle=The+heart+of+the+HIV+RNA+packaging+signal%3F&rft.volume=117&rft.issue=33&rft.date=2020-07-28&rft_id=info%3Adoi%2F10.1073%2Fpna&rft.aulast=Rein&rft.aufirst=Alan&rft_id=https%3A%2F%2Fpmc.ncbi.nlm.nih.gov%2Farticles%2FPMC7443930%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://www.britannica.com/science/J-psi-particle">"J/psi particle | Quark, Charm & Meson | Britannica"</a>. <i>www.britannica.com</i><span class="reference-accessdate">. Retrieved <span class="nowrap">2025-02-09</span></span>. <q>J/psi particle, type of meson consisting of a charmed quark and a charmed antiquark.</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=unknown&rft.jtitle=www.britannica.com&rft.atitle=J%2Fpsi+particle+%7C+Quark%2C+Charm+%26+Meson+%7C+Britannica&rft_id=https%3A%2F%2Fwww.britannica.com%2Fscience%2FJ-psi-particle&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSrivastavaVarmaAbhilashSharma2019" class="citation journal cs1">Srivastava, Manishi; Varma, Vishwanath; Abhilash, Lakshman; Sharma, Vijay Kumar; Sheeba, Vasu (June 2019). <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30939971/">"Circadian Clock Properties and Their Relationships as a Function of Free-Running Period in Drosophila melanogaster"</a>. <i>Journal of Biological Rhythms</i>. <b>34</b> (3): <span class="nowrap">231–</span>248. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1177%2F0748730419837767">10.1177/0748730419837767</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/1552-4531">1552-4531</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/30939971">30939971</a>. <q>... 2) accuracy (i.e., day-to-day stability of the phase relationship (ψ), where ψ is the duration between a phase of the rhythm and a phase of the external cycle) is greater for clocks with τ close to 24 h; ...</q></cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Journal+of+Biological+Rhythms&rft.atitle=Circadian+Clock+Properties+and+Their+Relationships+as+a+Function+of+Free-Running+Period+in+Drosophila+melanogaster&rft.volume=34&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E231-%3C%2Fspan%3E248&rft.date=2019-06&rft.issn=1552-4531&rft_id=info%3Apmid%2F30939971&rft_id=info%3Adoi%2F10.1177%2F0748730419837767&rft.aulast=Srivastava&rft.aufirst=Manishi&rft.au=Varma%2C+Vishwanath&rft.au=Abhilash%2C+Lakshman&rft.au=Sharma%2C+Vijay+Kumar&rft.au=Sheeba%2C+Vasu&rft_id=https%3A%2F%2Fpubmed.ncbi.nlm.nih.gov%2F30939971%2F&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBuchholz1986" class="citation journal cs1">Buchholz, W. (1986). <a rel="nofollow" class="external text" href="https://epub.ub.uni-muenchen.de/3841/1/3841.pdf">"A new System of proof-theoretic ordinal functions"</a> <span class="cs1-format">(PDF)</span>. <i>Ann. Pure Appl. Logic</i>. <b>32</b> (3): <span class="nowrap">195–</span>207. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2F0168-0072%2886%2990052-7">10.1016/0168-0072(86)90052-7</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Ann.+Pure+Appl.+Logic&rft.atitle=A+new+System+of+proof-theoretic+ordinal+functions&rft.volume=32&rft.issue=3&rft.pages=%3Cspan+class%3D%22nowrap%22%3E195-%3C%2Fspan%3E207&rft.date=1986&rft_id=info%3Adoi%2F10.1016%2F0168-0072%2886%2990052-7&rft.aulast=Buchholz&rft.aufirst=W.&rft_id=https%3A%2F%2Fepub.ub.uni-muenchen.de%2F3841%2F1%2F3841.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3APsi+%28Greek%29" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><a class="external text" href="https://en.wikisource.org/wiki/Template:GHGbible-ref">Gesenius' Hebrew Grammar</a></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text">Unicode Code Charts: <a rel="nofollow" class="external text" href="https://www.unicode.org/charts/PDF/U0370.pdf">Greek and Coptic (Range: 0370-03FF)</a></span> </li> </ol></div>    </div><noscript><img src="https://login.wikimedia.org/wiki/Special:CentralAutoLogin/start?useformat=desktop&type=1x1&usesul3=0" alt="" width="1" height="1" style="border: none; position: absolute;"></noscript> <div class="printfooter" data-nosnippet="">Retrieved from "<a dir="ltr" href="https://en.wikipedia.org/w/index.php?title=Psi_(Greek)&oldid=1274866346">https://en.wikipedia.org/w/index.php?title=Psi_(Greek)&oldid=1274866346</a>"</div></div> <div id="catlinks" class="catlinks" data-mw="interface"><div id="mw-normal-catlinks" class="mw-normal-catlinks"><a href="/wiki/Help:Category" title="Help:Category">Category</a>: <ul><li><a href="/wiki/Category:Greek_letters" title="Category:Greek letters">Greek letters</a></li></ul></div><div id="mw-hidden-catlinks" class="mw-hidden-catlinks mw-hidden-cats-hidden">Hidden categories: <ul><li><a href="/wiki/Category:Articles_with_short_description" title="Category:Articles with short description">Articles with short description</a></li><li><a href="/wiki/Category:Short_description_is_different_from_Wikidata" title="Category:Short description is different from Wikidata">Short description is different from Wikidata</a></li><li><a href="/wiki/Category:Wikipedia_indefinitely_semi-protected_pages" title="Category:Wikipedia indefinitely semi-protected pages">Wikipedia indefinitely semi-protected pages</a></li><li><a href="/wiki/Category:Articles_needing_additional_references_from_May_2013" title="Category:Articles needing additional references from May 2013">Articles needing additional references from May 2013</a></li><li><a href="/wiki/Category:All_articles_needing_additional_references" title="Category:All articles needing additional references">All articles needing additional references</a></li><li><a href="/wiki/Category:Articles_containing_Greek-language_text" title="Category:Articles containing Greek-language text">Articles containing Greek-language text</a></li><li><a href="/wiki/Category:Pages_with_Greek_IPA" title="Category:Pages with Greek IPA">Pages with Greek IPA</a></li><li><a href="/wiki/Category:Pages_with_plain_IPA" title="Category:Pages with plain IPA">Pages with plain IPA</a></li><li><a href="/wiki/Category:All_articles_with_unsourced_statements" title="Category:All articles with unsourced statements">All articles with unsourced statements</a></li><li><a href="/wiki/Category:Articles_with_unsourced_statements_from_June_2024" title="Category:Articles with unsourced statements from June 2024">Articles with unsourced statements from June 2024</a></li></ul></div></div> </div> </main> </div> <div class="mw-footer-container"> <footer id="footer" class="mw-footer" > <ul id="footer-info"> <li id="footer-info-lastmod"> This page was last edited on 9 February 2025, at 18:14<span class="anonymous-show"> (UTC)</span>.</li> <li id="footer-info-copyright">Text is available under the <a href="/wiki/Wikipedia:Text_of_the_Creative_Commons_Attribution-ShareAlike_4.0_International_License" title="Wikipedia:Text of the Creative Commons Attribution-ShareAlike 4.0 International License">Creative Commons Attribution-ShareAlike 4.0 License</a>; additional terms may apply. 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