Source : Webster's Revised Unabridged Dictionary (1913)

Cockateel \Cock"a*teel\, n. (Zo["o]l.)
   An Australian parrot ({Calopsitta Nov[ae]-Hollandi[ae]}); --
   so called from its note.

Source : WordNet®

cockateel
     n : small gray Australian parrot with a yellow crested head
         [syn: {cockatiel}, {cockatoo parrot}, {Nymphicus
         hollandicus}]