Etymology

From a Late Latin *mustaceus, Vulgar Latin *mustaceus, from Byzantine Greek μουστάκιον ‎(moustákion), diminutive of (Doric) Ancient Greek μύσταξ ‎(mústax, “upper lip”), from Proto-Indo-European *mendʰ- ‎(“to chew”). Compare Aromanian mustatsã, French moustache, Neapolitan mustaccio, Romanian mustață, Sicilian mustazzu, Spanish mostacho.