crepitus

1. the grating sound heard when the ends of fractured bones rub together and also from arthritic joints. 2. the grating sound and pain in chondromalacia patellae, which is a roughening of the inner surface of the kneecap. 3. the sound heard by means of a STETHOSCOPE from an inflamed lung when there is fluid in the alveoli (see ALVEOLUS ).