Term: chlorine: a common nonmetallic element belonging to the halogens; best known as a heavy yellow irritating toxic gas; used to purify water and as a bleaching agent and disinfectant; occurs naturally only as a salt (as in sea water)
Broader: chemical element: any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter | Unrelated: rheumatoid arthritis: 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
Broader: chemical element: any of the more than 100 known substances (of which 92 occur naturally) that cannot be separated into simpler substances and that singly or in combination constitute all matter | Unrelated: sumo ring: the circular ring in which Sumo wrestlers compete