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 suit against the ethanol plant also alleged some excess discharges of chlorine and nitrogen ammonia. — Adriana Pérez, Chicago Tribune, 20 Aug. 2026

Your trusty beach towel is a magnet for sunscreen, chlorine, sand, and extra moisture—all of which can build up within fibers over time. — Caroline Lubinsky, Martha Stewart, 20 Aug. 2026

Although both helped mitigate the effects of the gas, urine offered some degree of chemical protection because its ammonia partially neutralized the chlorine, reducing the gas’s damaging and potentially lethal effects on the lungs. — Encyclopedia Britannica, 19 Aug. 2026

The filter significantly diminishes elements commonly found in water that can be damaging, like chlorine, hydrogen sulfide, heavy metals, and more. — Caroline Hughes, Travel + Leisure, 17 Aug. 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