Humpback \Hump"back`\, n. [Cf. {Hunchback}.]
1. A crooked back; a humped back. --Tatler.
[1913 Webster]
2. A humpbacked person; a hunchback.
[1913 Webster]
3. (Zool.)
(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 {Megaptera
osphyia} of America; that of the California coasts is
{Megaptera versabilis}.
(b) A small salmon ({Oncorhynchus gorbuscha}), of the
northwest coast of America; the {humpbacked salmon}.
[1913 Webster]