A common nonmetallic halogen element, found in the combined state only, chiefly with sodium as common salt (NaCl). Symbol, Cl. A greenish-yellow irritating toxic gas with a disagreeable odor; a respiratory irritant. Used for producing safe drinking water, paper products, dyestuffs, textiles, petroleum products, medicines, antiseptics, insecticides, foodstuffs, solvents, paints, plastics, and many other consumer products.