Source : Webster's Revised Unabridged Dictionary (1913)

Flycatcher \Fly"catch`er\, n. (Zo["o]l.)
   One of numerous species of birds that feed upon insects,
   which they take on the wing.

   Note: The true flycatchers of the Old World are Oscines, and
         belong to the family {Muscicapid[ae]}, as the spotted
         flycatcher ({Muscicapa grisola}). The American
         flycatchers, or tyrant flycatchers, are Clamatores, and
         belong to the family {Tyrannid[ae]}, as the kingbird,
         pewee, crested flycatcher ({Myiarchus crinitus}), and
         the vermilion flycatcher or churinche ({Pyrocephalus
         rubineus}). Certain American flycatching warblers of
         the family {Sylvicolid[ae]} are also called
         flycatchers, as the Canadian flycatcher ({Sylvania
         Canadensis}), and the hooded flycatcher ({S. mitrata}).
         See {Tyrant flycatcher}.

Source : WordNet®

flycatcher
     n 1: any of a large group of small songbirds that feed on insects
          taken on the wing [syn: {Old World flycatcher}, {true
          flycatcher}]
     2: large American birds that characteristically catch insects
        on the wing [syn: {New World flycatcher}, {tyrant
        flycatcher}, {tyrant bird}]