The Collaborative International Dictionary of English v.0.48:
Humpback whale \Hump"back` whale\, n. the humpback[3]. [PJC]WordNet (r) 3.0 (2006):
humpback whale n 1: large whalebone whale with long flippers noted for arching or humping its back as it dives [syn: humpback, humpback whale, Megaptera novaeangliae]