WordNet sense 1 (a mongrel hog with a thin body and long legs and a ridged back; a wild or semi-wild descendant of improved breeds; found chiefly in the southeastern United States):

razorbacked hog, razorback hog

WordNet sense 2 (any of several baleen whales of the family Balaenopteridae having longitudinal grooves on the throat and a small pointed dorsal fin):

rorqual

WordNet sense 3 (having a sharp narrow back):

razor-backed

WordNet sense 4 (having a back or backing, usually of a specified type):

backed