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

Abrasive cleaners like steel wool pads, bleach, and chlorine should always be avoided when cleaning stainless steel. —Ashlyn Needham, Southern Living, 19 Sep. 2025

Verdagy’s system borrows heavily from chlor-alkali, a century-old industrial electrochemical method used worldwide for chlorine production. —Kapil Kajal, Interesting Engineering, 17 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

The plant is undergoing a massive underground construction project that will add ultraviolet disinfection and a chlorine contact basin, to the 90 year old facility. —Chase Hunter, Mercury News, 9 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