Pronunciation: (mus'tash, mu-stash'),[key] —n. 1. the hair growing on the upper lip
2. such hair on men, allowed to grow without shaving, and often trimmed in any of various shapes.
3. hairs or bristles growing near the mouth of an animal.
4. a stripe of color, or elongated feathers, suggestive of a mustache on the side of the head of a bird.
5. something resembling a mustache, as food or drink adhering to the upper lip: a mustache of milk.Also,moustache.