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

These byproducts are responsible for that strong chlorine smell. —Lisa Cuchara, The Conversation, 23 July 2025

In response, the German Army developed deadly chlorine and mustard gases. —Emilie Le Beau Lucchesi, Discover Magazine, 17 July 2025

Popular hiking trails such as the North and South Kaibab trails and the Phantom Ranch area were closed due to a chlorine gas leak at a water treatment plant, officials said. —Perry Vandell, AZCentral.com, 16 July 2025

On July 12, fire damaged a water treatment facility, releasing dangerous chlorine gas. —John Tufts, IndyStar, 14 July 2025

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