phos·gene
noun/ˈfɒzdʒiːn/
/ˈfɑːzdʒiːn/
[uncountable]- a poisonous gas that was used as a chemical weapon during the First World War
光气，碳酰氯（第一次世界大战中用作化学武器） Word Originearly 19th cent.: from Greek phōs ‘light’ + -gen, with reference to its original production by the action of sunlight on chlorine and carbon monoxide.