A European bird (
Corvus frugilegus) resembling the crow, but smaller. It is black, with purple and violet reflections. The base of the beak and the region around it are covered with a rough, scabrous skin, which in old birds is whitish. It is gregarious in its habits. The name is also applied to related Asiatic species.
(Zool.)
“The rook . . . should be treated as the farmer's friend.”
— Pennant.