A whalebone whale(Balaena mysticetus)of Arctic seas, having a very large head and an arched upper jaw.
"blue whale:a very large whalebone whale (Sibbaldus musculus) having a bluish-gray back, yellow underparts, and several ventral throat grooves. It is considered the largest living animal, sometimes reaching a length of 30.5 meters (100 feet)."
large whalebone whale with long flippers noted for arching or humping its back as it dives.
large arctic whalebone whale; allegedly the `right' whale to hunt because of its valuable whalebone and oil.