The term "buttocks" refers to the two rounded portions of the body located at the back of the hips. They are composed of muscle and fat and play a significant role in movement, providing support and balance when sitting, standing, or walking.
The word "buttocks" comes from the Middle English term "buttok," which is derived from the Old English "buttuc," meaning "the part of the body that is behind." It is related to the term "butt," which refers to a similar part of the body.