chlorine
noun [ U ] uk/ˈklɔː.riːn/ us/ˈklɔːr.iːn/ (symbol Cl)
氯，氯气
a chemical element that is a greenish-yellow gas with a strong smell, added to water in order to kill organisms that might cause infection
The chlorine in the pool makes my eyes sore. 游泳池里的氯气刺得我眼睛发疼。