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

Most households have running water, disinfected at the source with chlorine, but the supply is uneven. —Bymartin Enserink, science.org, 6 Feb. 2025

Municipal water sources may have additives like chlorine or fluoride that can harm sensitive plants. —Mary Marlowe Leverette, Southern Living, 24 Jan. 2025

Municipalities turned to these substances as an alternative to chlorine, because chlorine’s byproducts in water have been associated with possible adverse health effects such as elevated risks of colon and bladder cancer, low birth weight, and miscarriage. —Tom Hawking, Popular Science, 22 Nov. 2024

For both types of jackets, avoid fabric softeners, heavily scented detergents, and chlorine bleach. —Mary Marlowe Leverette, Southern Living, 31 Jan. 2025

Word History

First Known Use

1810, in the meaning defined above

Phrases Containing chlorine

• chlorine dioxide
• chlorine monoxide

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