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).
1590s, "to divide speech into distinct parts" (earlier in a now-obsolete sense "to formally bring charges against," 1550s), from Latin articulatus, past participle of articulare "to separate into joints," also "to utter distinctly," from articulus "a part, a member, a joint" (see article).
Generalized sense of "express in words" is from 1690s. In a physical sense, "to join, to attach by joints," it is attested from 1610s. Earlier sense "to set forth in articles" (1560s) now is obsolete or nearly so. Related: Articulated; articulating.