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

This year, the company launched the FinWhale Smart Chlorine Dispenser, a free-floating device that continuously measures free chlorine and pH in the water. — Hannah Singleton, Time, 15 Oct. 2026

Test strips for quaternary ammonia and chlorine were expired. — Arkansas Online, 12 Oct. 2026

Prosecutors accused the two men of planning and acquiring the elements to make a chlorine bomb as well as using the internet to identify and research potential targets. — Issy Ronald, CNN Money, 3 Oct. 2026

Prosecutor Mark Luckett said the duo were directed by a third person believed to be in Iran who coordinated plans and provided instructions on making a homemade chlorine bomb. — ABC News, 3 Oct. 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