The Collaborative International Dictionary of English v.0.48:

Finch \Finch\ (f[i^]nch), n.; pl. Finches (f[i^]nch"[e^]z).
   [AS. finc; akin to D. vink, OHG. fincho, G. fink; cf. W. pinc
   a finch; also E. spink.] (Zool.)
   A small singing bird of many genera and species, belonging to
   the family Fringillid[ae].
   [1913 Webster]

   Note: The word is often used in composition, as in chaffinch,
         goldfinch, grassfinch, pinefinch, etc.
         [1913 Webster]

   Bramble finch. See Brambling.

   Canary finch, the canary bird.

   Copper finch. See Chaffinch.

   Diamond finch. See under Diamond.

   Finch falcon (Zool.), one of several very small East Indian
      falcons of the genus Hierax.

   To pull a finch, to swindle an ignorant or unsuspecting
      person. [Obs.] "Privily a finch eke could he pull."
      --Chaucer.
      [1913 Webster]

WordNet (r) 3.0 (2006):

finch
    n 1: any of numerous small songbirds with short stout bills
         adapted for crushing seeds