noun (n)

• any painful disorder of the joints or muscles or connective tissues(noun.state)

  source: wordnet30
• a chronic autoimmune disease with inflammation of the joints and marked deformities; something (possibly a virus) triggers an attack on the synovium by the immune system, which releases cytokines that stimulate an inflammatory reaction that can lead to the destruction of all components of the joint(noun.state)

  Synonym:
  atrophic arthritis, rheumatoid arthritis
  

  source: wordnet30
• A general disease characterized by painful, often multiple, local inflammations, usually affecting the joints and muscles, but also extending sometimes to the deeper organs, as the heart.(noun)

  source: webster1913