What is "chlorine dioxide"

n. a reddish-yellow explosive gas, ClO₂, used as a water disinfectant and to bleach flour and wood pulp

n. an explosive gas (ClO2) used chiefly in bleaching paper or starch or soap or flour and in water purification

Chlorine dioxide is a chemical compound with the formula ClO. This yellowish-green gas crystallizes as bright orange crystals at −59 °C. As one of several oxides of chlorine, it is a potent and useful oxidizing agent used in water treatment and in bleaching.