My father was a good-for-nothing layabout who sat about on his posterior all day and ate potato chips.

The deadlift is a compound movement that trains the gluteus maximus, hamstrings, and other muscles in the posterior chain such as the erector spinae.

Tom has a posterior hip dislocation.

The patient injured his upper cervical posterior spinal artery by sneezing.

Philosophers distinguish between a priori and a posteriori knowledge.