antioxidant

noun

an·​ti·​ox·​i·​dant ˌan-tē-ˈäk-sə-dənt 

ˌan-ˌtī-

: a substance (such as beta-carotene or vitamin C) that inhibits oxidation or reactions promoted by oxygen, peroxides, or free radicals

antioxidant adjective

Examples of antioxidant in a Sentence

Recent Examples on the Web

But this formula also pairs caffeine with antioxidants and glycyrrhetinic acid to brighten and firm the entire eye area. —Brianna Peters, Vogue, 22 Apr. 2026

Meanwhile, antioxidant-rich Mandarin orange extract soothes and seals in moisture for a plumper, dewier finish. —Jennifer Hussein, Allure, 21 Apr. 2026

Chia Seeds Chia seeds are rich in soluble fiber and quercetin, an antioxidant that may support heart health by reducing inflammation. —Abby Norman, Verywell Health, 21 Apr. 2026

What Happens to the Body During Earthing The electrons absorbed through skin contact are thought to act as natural antioxidants, neutralizing free radicals — unstable molecules that contribute to cellular inflammation and tissue damage. —Allison Palmer, Fort Worth Star-Telegram, 21 Apr. 2026

Word History

First Known Use

1919, in the meaning defined above

Rhymes for antioxidant

• oxidant

Kids Definition

antioxidant

noun

an·​ti·​ox·​i·​dant ˌant-ē-ˈäk-səd-ənt 

ˌan-ˌtī-

: a substance that opposes oxidation or prevents or makes difficult reactions made easier by oxygen

Medical Definition

antioxidant

noun

an·​ti·​ox·​i·​dant ˌant-ē-ˈäk-səd-ənt, ˌan-ˌtī- 

: any of various substances (as beta-carotene, vitamin C, and alpha-tocopherol) that inhibit oxidation or reactions promoted by oxygen and peroxides and that include many held to protect the living body from the deleterious effects of free radicals

antioxidant adjective