word-forming element meaning "two, having two, twice, double, doubly, twofold, once every two," etc., from Latin bi- "twice, double," from Old Latin dvi- (cognate with Sanskrit dvi-, Greek di-, dis-, Old English twi-, German zwei- "twice, double"), from PIE root *dwo- "two."
Nativized from 16c. Occasionally bin- before vowels; this form originated in French, not Latin, and might be partly based on or influenced by Latin bini "twofold" (see binary). In chemical terms, it denotes two parts or equivalents of the substance referred to. Cognate with twi- and di- (1).
"pertaining to the lips," 1590s, from Medieval Latin labialis "having to do with the lips," from Latin labium "lip" (see lip (n.)). The noun meaning "a labial sound" (one accomplished by complete closure of the lips) is from 1660s, from the adjective in this sense (1590s). Related: Labially.
<a href="https://www.etymonline.com/word/bilabial">Etymology of bilabial by etymonline</a>
Harper, D. (n.d.). Etymology of bilabial. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/bilabial