noun
also be·lou·ga bəˈlügə
( -s )
Etymology: Russian byeluga, from byely white; akin to Old Slavic byelŭ white, Sanskrit bhāti he shines — more at fancy
1. : a white sturgeon ( Acipenser huso ) of the Black sea, Caspian sea, and their tributaries that reaches a length of 18 feet and has a swim bladder that is used to make isinglass and roe that is made into caviar
2.
[Russian byelukha, from byely white]
: a cetacean ( Delphinapterus leucas ) of the family Delphinidae becoming about 10 feet long and white when adult and occurring chiefly in northern seas and especially in the lower St. Lawrence river — called also white whale