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

Add in three old bath towels, along with laundry detergent for a regular-sized load and 2 cups of chlorine bleach, then run the cycle. —Karen Brewer Grossman, Southern Living, 18 Oct. 2025

The chlorine sanitation solution measured zero parts per million. —David J. Neal, Miami Herald, 17 Oct. 2025

The warewash area lacked chlorine. —Camila Pedrosa, Sacbee.com, 17 Oct. 2025

Compared to existing methods to recover rare earth elements, a process based on rapidly heating waste magnet material in the presence of chlorine gas uses one-third of the processing steps, reduces energy consumption by 87 percent, and produces 84 percent fewer greenhouse gas emissions. —IEEE Spectrum, 9 Oct. 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