dorsal

adjectives

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

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

dorsal

is derived from

is derived from

antonym

facing away from the axis of an organ or organism

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

abaxial, dorsal