n.
Pronunciation: ' p ī
Function: noun
Inflected Form: plural pis \ ' p ī z \
Etymology: Middle Greek, from Greek pei, of Semitic origin; akin to Hebrew p ē pe
Date: 1638
1 : the 16th letter of the Greek alphabet ― see ALPHABET table
2 a : the symbol π denoting the ratio of the circumference of a circle to its diameter b : the ratio itself : a transcendental number having a value rounded to eight decimal places of 3.14159265