What does "blackbird" mean?

Blackbird: 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 Agelæus phoeniceus, or red-winged blackbird; the cowbird; the rusty grackle, etc. See Redwing.