What is the medical term for the movement that raises the arms laterally away from the body?

The movement that raises the arms laterally away from the body is referred to as abduction. This term specifically describes the action of moving a limb or body part away from the midline. In the context of the upper extremities, when the arms are lifted out to the side, this movement results in an increase in the angle between the arms and the torso, thereby illustrating abduction.

Flexion pertains to decreasing the angle between body parts, such as bending the elbow. Adduction, on the other hand, is the movement of bringing limbs closer to the midline of the body, which contrasts with the outward, lateral motion described in the question. Rotational motion refers to the turning of a body part around its axis, which does not accurately define the lateral lifting of the arms. This clarity in definitions highlights why "abduction" is the correct choice.