- pi (n.)
[pi 词源字典]
- Greek letter, from Hebrew, literally "little mouth." As the name of the mathematical constant, from 1841 in English, used in Latin 1748 by Swiss mathematician Leonhart Euler (1707-1783), as an abbreviation of Greek periphereia "periphery." For the meaning "printer's term for mixed type," see pie (3).[pi etymology, pi origin, 英语词源]