dorsum
dor.sum \'do.r-s*m\ \-s*\ n or dorsa [L] pl 1: BACK; esp : the entire dorsal surface of an animal 2: the upper surface of an appendage or part
dor.sum \'do.r-s*m\ \-s*\ n or dorsa [L] pl 1: BACK; esp : the entire dorsal surface of an animal 2: the upper surface of an appendage or part