Final answer:
A partial separation of a joint is known as a subluxation, which can lead to pain and instability.
Step-by-step explanation:
A partial separation of a joint, or partial dislocation, is known as a subluxation. This type of injury is different from a complete dislocation in that only a partial separation between the articulating surfaces of the joint occurs. In a subluxation, the bone is only partly out of its usual anatomical position. Subluxations can result in pain, instability, and sometimes a noticeable deformity.