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 no-lather cleanser uses chelation technology to remove mineral buildup from hard water and chlorine, a common issue for coarse curls that appear dull or rough. —Jamie Wilson, Glamour, 20 Feb. 2026

Never use chlorine bleach, oxygen bleach (sodium percarbonate), or baking soda on cashmere, Theresa warns. —Olivia McIntosh, Martha Stewart, 15 Feb. 2026

Radical transparency means admitting mistakes Armedangels prides itself on using only chlorine-free wool from certified organic farms. —Jasmin Malik Chua, Sourcing Journal, 13 Feb. 2026

Health inspectors found containers of chlorine stored over a bag of onions. —Veronica Fernandez-Alvarado february 13, Sacbee.com, 13 Feb. 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