In a joint, crepitus can indicate cartilage wear in the joint space. The term "crepitus" is derived from the Latin, meaning "a crackling sound or rattle." Typically, crepitus is a grinding noise coupled with a sensation in the affected joint. Crepitus can occur with or without pain.
New Webster's Medical Dictionary, Second Edition. 2003. MedicineNet.com
Osteoarthritis - Patient Education. American College of Rheumatology. June 2006.