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.