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

It’s also packed with antioxidants, which help protect hair from UV light and other external aggressors. — Deanna Pai, Glamour, 10 Sep. 2026

Steaming, baking, and microwaving may preserve some, though not all, nutrients and antioxidants. — Lauren Panoff, Verywell Health, 9 Sep. 2026

This is because these teas contain high levels of antioxidants. — Merve Ceylan, HEALTH, 9 Sep. 2026

The antioxidants help cells revitalize, and the anti-inflammatory properties can help relieve the nasty side effects of cold and touches of flu in the body. — Bestreviews, Chicago Tribune, 4 Sep. 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