Located away from the centre of the main body.
In the case of an appendage, such as a limb, this is away from the point of attachment to the main body.
Distal is often used as a relative term to indicate where something is located along the proximodistal axis i.e. that it is further from, or more distant to, the centre of the body or to the point of attachment to the main body.
For example, the wrist is distal to the elbow, but proximal to the thumb.