Posterior comes from the Latin word posterus, meaning "coming after". Posterior is often used as a technical term in biology and medicine to refer to the back side of things, and is the opposite of anterior, which refers to the front side.

What does posterior in medical terms mean?

Posterior comes from the Latin word posterus, meaning "coming after". Posterior is often used as a technical term in biology and medicine to refer to the back side of things, and is the opposite of anterior, which refers to the front side.

Why do people say sitting on your posterior?

The prefix post means “after,” and things that are posterior come after the things in the front. The opposite of posterior is anterior, which refers to the front, usually of body parts. You can also use the word posterior to jokingly refer to the part of your body that you sit on — your backside.