dorsal
1. [ adjective ] belonging to or on or near the back or upper surface of an animal or organ or part
Examples:

"the dorsal fin is the vertical fin on the back of a fish and certain marine mammals"

Related terms: ventral
2. [ adjective ] (biology) facing away from the axis of an organ or organism
Synonyms: abaxial
Examples:

"the abaxial surface of a leaf is the underside or side facing away from the stem"

Related terms: adaxial biology
Similar spelling:   dorsally
  doorsill