Which medical term would describe a backward movement?

The term that describes a backward movement is "retro." In medical terminology, the prefix "retro-" specifically indicates a position or movement that is backward or behind. For example, in anatomy, "retroperitoneal" refers to structures located behind the peritoneum. This is significant in various medical contexts, as understanding directional terms is essential for effective communication in healthcare.

The other options represent different concepts: “ante” means "before" or "in front of," signifying a position in the forward direction; “pro” suggests "in favor of" or can denote something that is in front of or supportive; and “trans” indicates "across" or "through," referring to movement from one side to another. Knowing these distinctions helps clarify anatomical relationships and movements in medical discussions.