1585, from Fr.
moustache, from It.
mostaccio, from Medieval Gk.
moustakion, dim. of Doric
mystax (gen.
mystakos) "upper lip, mustache," related to
mastax "jaws, mouth," lit. "that with which one chews," from PIE base
*mnto- "mouth" (see
mouth). Borrowed earlier (1551) as
mostacchi, from the It. word or its Sp. derivative
mostacho. The plural form of this,
mustachios, lingers in English. Dutch slang has a useful noun,
de befborstel, to refer to the mustache specifically as a tool for stimulating the clitoris; probably from
beffen "to stimulate the clitoris with the tongue."