Nutcracker \Nut"crack`er\, n. 1. An instrument for cracking nuts. 2. (Zo["o]l.) (a) A European bird ({Nucifraga caryocatactes}), allied to the magpie and crow. Its color is dark brown, spotted with white. It feeds on nuts, seeds, and insects. (b) The American, or Clarke's, nutcracker ({Picicorvus Columbianus}) of Western North America.