πῖ

Forms

πῖ (pî) n (indeclinable)^[1] The older spelling is πεῖ (peî), whose ⟨ει⟩ stood for a long close /eː/.^[2][3][4]

Etymology

It is the later spelling of πεῖ (peî),^[5][3] the letter name borrowed from Phoenician 𐤐 (pē).^[1][2][3] Rosół lists it among the Greek letter names taken from Semitic: the Semitic name of the letter, found in Hebrew, Aramaic and Syriac, was originally a noun meaning “mouth”, as in Akkadian pû.^[6]

Ancient writers explained it otherwise: the lexicon of Zonaras derives it from παίω (paíō, “to strike”), because the sound is like that of a blow.^[7]

Earliest recorded meaning

The name is first found, spelled πεῖ, in the comic poet Callias in the 5th century BC and in Plato.^[6][8][9] The spelling πῖ appears in Plutarch and in the scholia to Dionysius Thrax.^[10][5]

Semantic evolution

Π is the sixteenth letter of the Greek alphabet; as a numeral π′ stood for 80, and in inscriptions Π was also used for 5, as the initial of πέντε (pénte).^[11][12]

The name survives as Modern Greek πι (pi), which also describes things shaped like the letter, and in the phrase στο πι και φι, “in a trice”.^[13] Πάπυρος explains that phrase from the medieval use of π and φ as the initials of the words for the stake and the gallows, to which offenders were sent without delay.^[14] The Swiss mathematician Leonhard Euler used π in Latin in 1748 for the ratio of a circle's circumference to its diameter, as an abbreviation of περιφέρεια (periphéreia), and English uses pi for that constant from 1841.^[15] Finnish pii is borrowed from the Greek name.^[1]

Timeline

• 5th century BC – The comic poet Callias uses the name, spelled πεῖ.^[6][9]
• 5th–4th century BC – Plato uses the name πεῖ.^[8][10][9]
• 1st–2nd century AD – Plutarch writes the name as πῖ.^[10][9]
• 13th century – The lexicon of Zonaras derives the name from παίω (paíō).^[7]
• 1748 – Euler uses π for the ratio of a circle's circumference to its diameter.^[15]
• 1841 – English uses pi for the mathematical constant.^[15]
• Modern Greek – πι (pi) is the name of the letter.^[13][14]

Meanings

Noun

1. Pi, the name of the letter Π, π.^{[5][8][11][16]}

Related words

• πεῖ (peî)
• English pi

References

1. ^ a b c d e f Wiktionary, the free dictionary, https://en.wiktionary.org
2. ^ a b Beekes, Robert S. P. (2010), Etymological Dictionary of Greek, with the assistance of Lucien van Beek, Leiden Indo-European Etymological Dictionary Series 10, Leiden; Boston: Brill
3. ^ a b c Chantraine, Pierre (2009), Dictionnaire étymologique de la langue grecque: histoire des mots, new ed. with a supplement (Chroniques d'étymologie grecque 1–10), Paris: Klincksieck
4. ^ Frisk, Hjalmar (1960–1972), Griechisches etymologisches Wörterbuch, 3 vols, Heidelberg: Carl Winter
5. ^ a b c Liddell, Henry George; Scott, Robert; Jones, Henry Stuart (1940), A Greek-English Lexicon, 9th ed., Oxford: Clarendon Press
6. ^ a b c Rosół, Rafał (2013), Frühe semitische Lehnwörter im Griechischen, Frankfurt am Main: Peter Lang
7. ^ a b Pseudo-Zonaras, Lexicon, ed. Johann August Heinrich Tittmann (1808), Iohannis Zonarae Lexicon, Leipzig: Crusius
8. ^ a b c Diggle, James, et al., eds. (2021), The Cambridge Greek Lexicon, Cambridge: Cambridge University Press
9. ^ a b c d Rodríguez Adrados, Francisco, et al., eds. (1980–), Diccionario Griego-Español, Madrid: CSIC, http://dge.cchs.csic.es/xdge
10. ^ a b c Keersmaekers, Alek (2021–2025), GLAUx: The Greek Language Automated corpus, https://github.com/alekkeersmaekers/glaux
11. ^ a b Bailly, Anatole (1901), Abrégé du dictionnaire grec-français, Paris: Hachette
12. ^ Liddell, Henry George; Scott, Robert (1889), An Intermediate Greek-English Lexicon, Oxford: Clarendon Press
13. ^ a b Ινστιτούτο Νεοελληνικών Σπουδών (Ίδρυμα Μανόλη Τριανταφυλλίδη) (1998), Λεξικό της κοινής νεοελληνικής, Thessaloniki: Aristotle University of Thessaloniki
14. ^ a b Πάπυρος–Larousse–Britannica, Μέγα Λεξικό της Ελληνικής Γλώσσας, Athens: Πάπυρος
15. ^ a b c Harper, Douglas. Online Etymology Dictionary, https://www.etymonline.com
16. ^ Korinthios, J. (2025), Grande Dizionario Greco Classico: Greco–Italiano, digital ed., Milan: Hoepli