[mass noun](Chemistry)a colourless poisonous gas made by the reaction of chlorine and carbon dioxide. It was used as a poison gas, notably in the First World War 光气
Alternative name: carbonyl chloride; chem. formula: COCl2 又名:碳酰氯;化学分子式:COCl2
语源
early 19th cent.: from Greek phōs 'light' + -gen, with reference to its original production by the action of sunlight on chlorine and carbon monoxide