Moustached means having a moustache: hair that grows on the upper lip, not the chin. Add -ed to moustache and you get an adjective, the same pattern as bearded. You will see it before a noun — a moustached man, a moustached actor — a little more in writing than in speech. In talk, people often say a man with a moustache instead. This spelling with ou is the British one; American English likes mustache, so you may also meet mustached. It talks only about that strip of hair, not a full beard. Though actually, you can also meet it in older descriptions of animals with similar markings on the face.