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

They're loaded with vitamin C, antioxidants, and other nutrients. —Chelsea Rae Bourgeois, Health, 1 July 2025

The drink also gives you a boost of hydration, antioxidants, and polyphenols. —Nick Blackmer, Verywell Health, 30 June 2025

Compounds in the plant’s twigs, leaves, and bark have also been recognized for their antioxidant and anti-inflammatory properties. —The Editors, JSTOR Daily, 27 June 2025

Blackberries, blueberries, cranberries, raspberries, and the like are tiny powerhouses of free radical-fighting antioxidants. —Alessandra Signorelli, Vogue, 23 June 2025

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