(n.) A bird of the Parrot family, of the subfamily Cacatuinae, 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 (Plictolophus, / Cacatua, cristatus), the sulphur-crested (P. galeritus), etc. The palm or great black cockatoo of Australia is Microglossus aterrimus.