The Collaborative International Dictionary of English v.0.48:

Blackbird \Black"bird\ (bl[a^]k"b[~e]rd), n. (Zool.)
   In England, a species of thrush (Turdus merula), a singing
   bird with a fin note; the merle. In America the name is given
   to several birds, as the Quiscalus versicolor, or crow
   blackbird; the Agel[ae]us ph[oe]niceus, or red-winged
   blackbird; the cowbird; the rusty grackle, etc. See
   Redwing.
   [1913 Webster]