Final answer:
The movement of a body part away from the central axis is called abduction, and muscles that perform this action are known as abductors.
Step-by-step explanation:
The term that describes the movement of a part of the body away from the central axis is known as abduction. An example of this is when you move your arms or legs laterally, such as lifting them straight out to the sides. In the context of muscles, a muscle that moves the leg away from the body is referred to as an abductor. This is in contrast to adduction, which is the movement of a part toward the midline of the body, such as bringing the limbs inward after they have been abducted.