also bi-metallic, "composed of two metals," 1864; see bi- "two" + metallic. In economics, "pertaining to the use of both silver and gold as standards in currency," 1876, from French bimétalique (Cornuschi).
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).
early 15c., "of metal, made from metal," from Latin metallicus "of or belonging to metal," from Greek metallikos, from metallon "metal, ore" (see metal). Specific use in chemistry, indicating the condition of a metal in which it exists by itself, not mineralized or combined with substances which convert it into an ore, is by 1797.
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Harper, D. (n.d.). Etymology of bimetallic. Online Etymology Dictionary. Retrieved $(datetime), from https://www.etymonline.com/word/bimetallic