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

Using chlorine bleach—Pozniak recommends against using chlorine bleach (not to be confused with oxygen bleach). —Daley Quinn, Southern Living, 4 Oct. 2025

OxyChem makes things like chlorine for water treatment, vinyl chloride for plastics and calcium chloride that’s used to treat icy roads along with an assortment of other chemicals. —Dave Smith, Fortune, 2 Oct. 2025

The new approach uses flash Joule heating (FJH), which rapidly raises material temperatures to thousands of degrees in milliseconds, combined with chlorine gas to extract REEs in seconds. —Neetika Walter, Interesting Engineering, 29 Sep. 2025

For example, a single chlorine atom from a CFC molecule can destroy over 100,000 ozone molecules before being neutralized. —Dianne Plummer, Forbes.com, 16 Sep. 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