Possible Definitions:
1. Rook (n.) Mist; fog. See Roke.
2. Rook (v. i.) To squat; to ruck.
3. Rook (n.) One of the four pieces placed on the corner squares of the board; a castle.
4. Rook (n.) 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.
5. Rook (n.) A trickish, rapacious fellow; a cheat; a sharper.