chlorine

noun

chlo·​rine ˈklȯr-ˌēn 

-ən

: a halogen element that is isolated as a heavy greenish-yellow diatomic gas of pungent odor and is used especially as a bleach, oxidizing agent, and disinfectant in water purification see Chemical Elements Table

Examples of chlorine in a Sentence

Recent Examples on the Web

Champion swimmer Dara Torres says that the chlorine in the pool actually helps her psoriasis. — Andrea Wurzburger, PEOPLE, 3 Aug. 2026

Cyclospora is resistant to the chlorine and sanitizers commonly used to sanitize fresh produce, and routine washing may not completely remove the parasite. — Lisa Cuchara, The Conversation, 29 July 2026

The main disinfectant used is chlorine gas, which has a high degree of toxicity, said engineer Josenrique Cueto, former director of the Miami-Dade Water and Sewer Department and former director of the Cuban American Association of Civil Engineers. — Sarah Moreno, Miami Herald, 24 July 2026

Days flow between cycling through the vineyards, swimming in the chlorine-free natural pool, and unwinding in the 3,600-square-metre Lake Spa with adults-only and family areas, indoor and outdoor pools, and saunas. — Jason Phillips, USA Today, 22 July 2026

Word History

First Known Use

1810, in the meaning defined above

Phrases Containing chlorine

• chlorine dioxide
• chlorine monoxide

Rhymes for chlorine

• taurine
• organochlorine

Kids Definition

chlorine

noun

chlo·​rine ˈklō(ə)r-ˌēn 

ˈklȯ(ə)r-, 

-ən

: a nonmetallic element that is found alone as a heavy greenish yellow irritating gas having two atoms per molecule and a strong odor and that is used especially as a bleach, oxidizing agent, and disinfectant in water purification see element

Medical Definition

chlorine

noun

chlo·​rine ˈklō(ə)r-ˌēn, ˈklȯ(ə)r-, -ən 

: a halogen element that is isolated as a heavy greenish yellow gas of pungent odor and is used especially as a bleach, oxidizing agent, and disinfectant in water purification

—symbol Cl see Chemical Elements Table