Know how to use "fewer" and "less"? Find out.
word-forming element meaning "twice," from Latin bis "twice, in two ways, doubly," from Old Latin dvis, cognate with Sanskrit dvih, Avestan bish, Greek dis, Middle High German zwis "twice," from PIE *dwo- "two" (see two). Also the form of bi- used before -s-, -c-, or a vowel.
Two; twice: bisalbuminemia.
Having two identical but separated complex chemical groups in one molecule: 1,4-bis(5-phenyloxazol-2-yl)-benzene.