1. a poisonous greenish-yellow gas that is a chemical element, used especially to disinfect water and in making bleach

Examples

• The swimming pool smelled strongly of chlorine.
• Chlorine is added to drinking water to kill harmful bacteria.
• The janitor used a chlorine-based cleaner to disinfect the bathroom.
• Chlorine gas was first discovered in 1774.
• Many household bleaches contain chlorine compounds.
• The water treatment plant monitors chlorine levels carefully.