Arthritis - Wikipedia, the free encyclopediaArthritis (from Greek arthro-, joint + -itis, inflammation; plural: arthritides) is a form of joint disorder that involves inflammation of one or more joints. There ...Arthritis | Define Arthritis at Dictionary.comnoun acute or chronic inflammation of a joint, often accompanied by pain and structural changes and having diverse causes, as infection, crystal deposition, or injury ...What Is Arthritis? - Arthritis Foundation | Symptoms Treatments ...What Is Arthritis? While often referred to as if it were a single disease, arthritis is actually an umbrella term used for a group of more than 100 medical conditions ...