noun1.   another word for hunchback
2.  Also called: humpback whale a large whalebone whale, Megaptera novaeangliae, closely related and similar to the rorquals but with a humped back and long flippers: family Balaenopteridae
 3. a Pacific salmon, Oncorhynchus gorbuscha, the male of which has a humped back and hooked jaws
  4.  Also called: humpback bridge British a road bridge having a sharp incline and decline and usually a narrow roadway
  Word origin
C17: alteration of earlier 
crumpbacked, perhaps influenced by 
hunchback; perhaps related to Dutch 
homp lump