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

Test results showed that a spike in chlorine levels from an unknown source led to the massive fish kill, although turtles, ducks and other wildlife weren’t affected. — Elizabeth Campbell, Fort Worth Star-Telegram, 30 June 2026

At this point, one-half to two-thirds of the ozone-eating chlorine up there was still carbon tetrachloride rather than CFCs. — Scott K. Johnson, ArsTechnica, 29 June 2026

These can help keep the right amount of chlorine in your pool, which aids in sanitation and keeping algae at bay. — Bestreviews, Chicago Tribune, 29 June 2026

The most common sanitizer used in home kitchens is chlorine bleach. — Mary Marlowe Leverette, The Spruce, 28 June 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