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

The formula is plant-based and fragrance is from essential oils—no ammonia, chlorine, or synthetic dyes. —Jamie Thilman, Bon Appetit Magazine, 22 Apr. 2026

Threats to the ozone layer continue, from, for example, chlorine-containing molecules emitted by massive wildfires and aluminum oxide produced when satellites and other space objects burn up upon reentry into the atmosphere. —Andrea Thompson, Scientific American, 22 Apr. 2026

The New York Times and France24 reported that the SAF had used chlorine gas against the RSF on at least two occasions. —Laura Kelly, The Hill, 16 Apr. 2026

Clean and disinfect surfaces with a mixture of detergent and chlorine bleach after someone’s sick, WebMD said. —Don Sweeney april 14, Sacbee.com, 14 Apr. 2026

Word History

First Known Use

1810, in the meaning defined above

Phrases Containing chlorine

• chlorine dioxide
• chlorine monoxide

Rhymes for chlorine

• 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