The Collaborative International Dictionary of English v.0.48:

Goldfinch \Gold"finch`\, n. [AS. goldfinc. See Gold, and
   Finch.] (Zool.)
   (a) A beautiful bright-colored European finch (Carduelis
       elegans). The name refers to the large patch of yellow
       on the wings. The front of the head and throat are bright
       red; the nape, with part of the wings and tail, black; --
       called also goldspink, goldie, fool's coat,
       drawbird, draw-water, thistle finch, and sweet
       William.
   (b) The yellow-hammer.
   (c) A small American finch (Spinus tristis); the thistle
       bird.
       [1913 Webster]

   Note: The name is also applied to other yellow finches, esp.
         to several additional American species of Spinus.
         [1913 Webster]

WordNet (r) 3.0 (2006):

goldfinch
    n 1: American finch whose male has yellow body plumage in summer
         [syn: New World goldfinch, goldfinch, yellowbird,
         Spinus tristis]
    2: small European finch having a crimson face and yellow-and-
       black wings [syn: goldfinch, Carduelis carduelis]