1. See white whale. 2. A large white sturgeon (Huso huso) of the Black and Caspian seas, whose roe is processed into caviar. Also called beluga sturgeon, whitefish.
ETYMOLOGY:
Russian belukha, white whale, and beluga, sturgeon : bely, white; see bhel-1 in Appendix I + -uga, -ukha, augmentative suff.