What is the anatomical term that describes something positioned on the opposite side of the body?

The term that describes something positioned on the opposite side of the body is "contralateral." This term is commonly used in anatomy and clinical contexts to indicate that a structure or condition exists on the side opposite to a reference point, typically relating to pairs, such as limbs or organs. For example, if you have an injury to your right arm, the left arm is considered contralateral to that injury.

The other terms do not convey the same meaning: "proximal" refers to something that is closer to the point of attachment or origin within the body's anatomy; "medial" indicates a position closer to the midline of the body; and "lateral" describes something that is further away from the midline. Understanding these terms is crucial for accurately describing the locations and relationships between different parts of the body in both healthy and clinical scenarios.