What is the term for direction toward the back of the body?

The term that refers to the direction toward the back of the body is "posterior." In anatomical terminology, the posterior (or dorsal) direction is used to describe structures that are located towards the backside of an organism. For example, in humans, the spine is considered posterior because it is toward the back, while the chest is anterior (toward the front).

In contrast, medial refers to a position closer to the midline of the body, which does not convey information about the back or front orientation. Anatomical is a general term that describes the standard terms of body orientation and structure but does not specifically indicate a direction. Superficial refers to a position closer to the surface of the body, rather than describing a back-facing orientation. Therefore, "posterior" is the precise term used to convey the directional reference toward the back of the body.