The Collaborative International Dictionary of English v.0.48:
Mustachio \Mus*ta"chio\, n.; pl. Mustachios. A mustache. --Longfellow. [1913 Webster]WordNet (r) 3.0 (2006):
mustachio n 1: a large bushy moustache (with hair growing sometimes down the sides of the mouth) [syn: mustachio, moustachio, handle-bars]