Crepitus = creaking
Crepitus be referred to 2 kinds of descriptive term during examination: 1) a sound heard during movement and/or 2) the palpable sensation of "lack of smoothness in the joint" noted by the examiner during range of motion testing in the ankle.
It can be from the bones in the ankle rubbing. It can be from swelling. It can be due to offset in the position of the joint.