dorsum

nouns

the posterior part of a human (or animal) body from the neck to the end of the spine

"his back was nicely tanned"

back, dorsum

is derived from

the back of the body of a vertebrate or any analogous surface (as the upper or outer surface of an organ or appendage or part)

"the dorsum of the foot"

dorsum

is derived from

is a type of (narrower)

any part of an organism such as an organ or extremity