(1) Pertaining to the back or any dorsum. SYN: tergal. (2) [TA], SYN: posterior (1). (3) In veterinary anatomy, pertaining to the back or upper surface of an animal. Often used to indicate the position of one structure relative to another; i.e., nearer the back surface of the body. (4) Old term meaning thoracic, in a limited sense; e.g., dorsal vertebrae. [Mediev. L. dorsalis, fr. dorsum, back]