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

This healthy green soup offers fiber and protein from the beans, and vitamins, minerals, and antioxidants from superfood Swiss chard. —Patricia Shannon, Southern Living, 21 Jan. 2026

The lightweight, deeply hydrating and nourishing cream has antioxidants, squalene, and ceramides. —Brianna J. Heath, Essence, 20 Jan. 2026

Adding berries provides more fiber and antioxidants, which support healthy cholesterol levels. —Julie Scott, Verywell Health, 20 Jan. 2026

Are antioxidants good for dull skin? —Jacqueline Kilikita, Refinery29, 20 Jan. 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