单词 hexad 释义 hexad|hksd|[ad. Gr. ἑά, -- a group of six, f. ἕ six.]1. The number six (in the Pythagorean System); a series of six numbers.1660Stanley Hist. Philos. ix. x. (1687) 528/1 The Pythagoreans held the number Six to be perfect..The names of...