Hump"back` (?), n. [Cf. Hunchback.] 1. A crooked back; a humped back. Tatler.

2. A humpbacked person; a hunchback.

3. (Zoöl.) (a) Any whale of the genus Megaptera, characterized by a hump or bunch on the back. Several species are known. The most common ones in the North Atlantic are Megaptera longimana of Europe, and M. osphyia of America; that of the California coasts is M. versabilis. (b) A small salmon (Oncorhynchus gorbuscha), of the northwest coast of America.