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

Red apples, especially deeper red varieties, contain higher levels of anthocyanins, potent antioxidants. — Cristina Mutchler, Verywell Health, 3 July 2026

Among the antioxidants in pomegranates, Syn notes, are polyphenols called anthocyanins, which give the fruit its deep red color. — Daryl Austin, USA Today, 2 July 2026

The formula also includes antioxidants like vitamin C, vitamin E, and cranberry fruit extract that help to brighten, hydrate, and protect your skin from environmental damage. — Essence Wiley, InStyle, 1 July 2026

Even if cherries aren’t your thing, there are plenty of other fruits that provide anti-inflammatory benefits and can even help your gut thanks to the presence of powerful antioxidants (like polyphenols and vitamin C) and fiber. — Laura Solla, Vogue, 1 July 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