chlorine

1 of 2

noun (1)

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

chlorin

2 of 2

noun (2)

chlo·​rin

ˈklōrə̇n, 

-ȯr-

variants or less commonly chlorine

" 

-ōrˌēn, 

-ȯˌrēn

plural -s

: any of several derivatives of chlorophyll obtained by hydrolysis, removal of the magnesium, sometimes with replacement by another metal (as copper), and opening of the carbocyclic ring see chlorophyllin sense 2

Examples of chlorine in a Sentence

Recent Examples on the Web

Noun

The fire released chemicals including chlorine, chloramine and chlorine compounds, the Georgia Emergency Management and Homeland Security Agency said at the time. — Kristi Swartz, AJC.com, 26 June 2026

The result is a cleaner pool that requires less chlorine to maintain proper sanitation levels. — Jessica Safavimehr, Southern Living, 26 June 2026

On the rare occasion that a passing neutrino struck a chlorine nucleus, it would be transformed into a radioactive form of argon that could be detected and counted. — Simon Frantz, Quanta Magazine, 24 June 2026

Chemicals such as chlorine gas, bromine vapor, hydrogen chloride, hydrogen bromide, nitrogen trichloride, particulate matter, and other compounds are believed to have been released into the air, the lawsuit alleges. — Irene Wright, USA Today, 23 June 2026

Word History

Etymology

Noun (2)

chlorophyll + -in, -ine

First Known Use

Noun (1)

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