n. [ Malayan kakatūa. ] (Zool.) A bird of the Parrot family, of the subfamily Cacatuinæ, having a short, strong, and much curved beak, and the head ornamented with a crest, which can be raised or depressed at will. There are several genera and many species; as the broad-crested cockatoo (Plictolophus cristatus or Cacatua cristatus), the sulphur-crested (Cacatua galerita or Plictolophus galeritus), etc. The palm cockatoo or great black cockatoo of Australia is Probosciger aterrimus (formerly Microglossus aterrimus). [ 1913 Webster +PJC ]