Dictionary
dor•sum
Pronunciation: (dôr'sum), [key]—
n.,
—pl. -saPronunciation: (-su). [key]
Anat., Zool.
1. the back, as of the body.
2. the back or outer surface of an organ, part, etc.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.