n. 1 the sixteenth letter of the Greek alphabet. 2 (as π.) the symbol of the ratio of the circumference of a circle to its diameter (approx. 3.14159). øpi-meson = PION. [Gk: sense 2 f. Gk periphereia circumference]
PI
Meaning of PI in English
English main colloquial, spoken dictionary. Английский основной разговорный словарь. 2012