Which term best describes moving a body part closer to the midline?

The term that best describes moving a body part closer to the midline is adduction. In anatomical terms, adduction specifically refers to the movement of a limb or body part toward the center of the body. For example, when you bring your arms down to your sides after raising them, or when you move your legs together, you are performing adduction.

This movement contrasts with abduction, which is the action of moving a body part away from the midline. Flexion refers to bending a joint, decreasing the angle between two body parts, such as bending the elbow or knee. Extension, on the other hand, is the opposite of flexion: it involves straightening a joint and increasing the angle between body parts. Understanding these terms is crucial in anatomy and can help in interpreting movements and actions in various medical and physical contexts.