antimony (n.) Look up antimony at Dictionary.com
brittle metallic element, early 15c., from Old French antimoine and directly from Medieval Latin antimonium, an alchemist's term (used 11c. by Constantinus Africanus), origin obscure, probably a Latinization of Greek stimmi "powdered antimony, black antimony" (a cosmetic used to paint the eyelids), from some Arabic word (such as al 'othmud), unless the Arabic word is from the Greek or the Latin is from Arabic; probably ultimately from Egyptian stm "powdered antimony." In French folk etymology, anti-moine "monk's bane" (from moine).

As the name of a pure element, it is attested in English from 1788. Its chemical symbol Sb is for Stibium, the Latin name for "black antimony," which word was used also in English for "black antimony."