/beuh looh"geuh/ , n.
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 white whale . a cetacean, Delphinapterus leucas, of northern seas, that has a rounded head and is white when adult.
[ 1585-95; belúga (now regularly belúkha for the cetacean), equiv. to bél ( yi ) white + -uga, prob. earlier *-oga (cf. Czech pstruh, Pol pstrag trout *pistr- mottled + *-ogu a cognate suffix) ]