The Collaborative International Dictionary of English v.0.48:

Bunting \Bun"ting\, n. [Scot. buntlin, corn-buntlin, OE.
   bunting, buntyle; of unknown origin.] (Zool.)
   A bird of the genus Emberiza, or of an allied genus,
   related to the finches and sparrows (family
   Fringillid[ae]).
   [1913 Webster]

   Note: Among European species are the common or corn bunting
         (Emberiza miliaria); the ortolan (Emberiza
         hortulana); the cirl (Emberiza cirlus); and the
         black-headed (Granitivora melanocephala). American
         species are the bay-winged or grass (Po["o]c[ae]tes
         gramineus or Po[oe]cetes gramineus); the
         black-throated (Spiza Americana); the towhee bunting
         or chewink (Pipilo); the snow bunting (Plectrophanax
         nivalis); the rice bunting or bobolink, and others.
         See Ortolan, Chewick, Snow bunting, Lark
         bunting.
         [1913 Webster] Bunting

WordNet (r) 3.0 (2006):

Pooecetes gramineus
    n 1: common North American finch noted for its evening song
         [syn: vesper sparrow, grass finch, Pooecetes
         gramineus]