Source : Webster's Revised Unabridged Dictionary (1913)

Catbird \Cat"bird\, n. (Zo["o]l.)
   An American bird ({Galeoscoptes Carolinensis}), allied to the
   mocking bird, and like it capable of imitating the notes of
   other birds, but less perfectly. Its note resembles at times
   the mewing of a cat.

Source : WordNet®

catbird
     n 1: any of various birds of the Australian region whose males
          build ornamented structures resembling bowers in order
          to attract females [syn: {bowerbird}]
     2: North American songbird whose call resembles a cat's mewing
        [syn: {gray catbird}, {Dumetella carolinensis}]