1. (鱼或动物的)背部的，背上的，背侧的
Dorsal means relating to the back of a fish or animal.

1. facing away from the axis of an organ or organism

e.g. the abaxial surface of a leaf is the underside or side facing away from the stem

Synonym: abaxial

2. belonging to or on or near the back or upper surface of an animal or organ or part

e.g. the dorsal fin is the vertical fin on the back of a fish and certain marine mammals