Definition of: mustache

(məs·tash′, mus′tash) noun
1. The growth of hair on the upper lip of men: occasionally used in the plural, in reference to its two parts.
2. The hair or bristles growing near the mouth of an animal.
3. An old soldier: a brave old mustache: a gallicism. Also mus·ta′chio (-tä′shō): sometimes spelled moustache. [<F moustache <Ital. mostaccio face <Med. L mustacia <Gk. mystax upper lip <mastax mouth, jaws]
—mus·tached (məs·tasht′) adjective