This means back. Not back in the directional sense, but back in the physical sense. This word is used when an organism is in anatomic position and it is necessary to describe a feature on its body so that others can understand without actually seeing the organism where something is in reference to something else. This word is useful because although we may think of the dorsal surface as being the rear because our backs are to the rear, those people who study or treat other organisms have to be able to distinguish between the rear surface and the back. For example, a dog's dorsal surface is not its "rear", or posterior surface, but its "top", or superior surface.

Also see superior, anterior, posterior, ventral, cephalic, caudal, proximal, distal, medial, lateral, superficial, deep, prone, supine, plane, and region.