adjective / noun
posterior
pah-STEER-ee-er/pɑːˈstɪriər/
Located at the back of the body or another structure.
The horse's hindquarters occupy the posterior region of its body.

Etymology
The comparative of ‘coming after’ means ‘later’ or ‘farther behind.’ Applied to position rather than time, it describes something toward the back or behind another part.
In context
we have the posterior ramis which is going to supply a lot of the back the skin and the muscles of the back.
More examples
- The posterior teeth do most of the chewing.
- The diagram labels the posterior end of the fish.
- She lands on her posterior when the chair breaks.
Forms
posterior · posteriors
posteriorly adverb — Toward or at the back.