beluga

noun

1. Also called hausen. a white sturgeon, Huso huso, of the Black and Caspian seas, valued as a source of caviar and isinglass.
2. Also called sea canary, white whale. a cetacean, Delphinapterus leucas, of northern seas, that has a rounded head and is white when adult.

noun

1. a large white sturgeon, Acipenser (or Huso) huso, of the Black and Caspian Seas: a source of caviar and isinglass
2. another name for white whale

n.

1590s, from Russian beluga, literally “great white,” from belo- “white” (from PIE *bhel-o-, from root *bhel- (1) “to shine, flash, burn;” see bleach (v.)) + augmentative suffix -uga. Originally the great sturgeon, found in the Caspian and Black seas; later (1817) also the small white whale (Delphinapterus leucas) found in northern seas.