pi

pi · noun¹

1. Proto-Semitic · derived from*pay-“mouth”
2. Ancient Greek · derived fromπεῖ
3. Koine Greek · derived fromπῖ
4. English todaypi

From Koine Greek πῖ (pî), from Ancient Greek πεῖ (peî), ultimately from Proto-Semitic *pay- (“mouth”). Doublet of pe. Its mathematical use apparently stems from its use as the first letter in περιφέρεια (periphéreia, “periphery; circumference”) and was first cited in 1706 in the Synopsis Palmariorum Matheseos by William Jones.

pi · noun, verb, adjective²

Unclear. Possibly from the Greek letter (see Etymology 1) as a common example of non-alphabetic character, possibly from pica (“type size”) (see Etymology 3), possibly from pie referring to its mixed nature or pied (“checkered, multicoloured”).

pi · noun, adjective³

Abbreviations.

Pi · proper noun⁴

1. Mandarin · derived from郫
2. English todayPi

From Mandarin 郫 (Pí).

Words from the same roots