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

Many are packed with nourishing ingredients like hyaluronic acid, caffeine, peptides, and antioxidants, so coverage feels more like an extension of your skin-care routine than an extra layer sitting on top. — Christa Joanna Lee, Allure, 14 Aug. 2026

This includes hyaluronic acid, vitamin E, and other antioxidants that help even out signs of aging, such as dark spots and wrinkles. — Alanna Martine Kilkeary, Glamour, 13 Aug. 2026

Tomatoes, spinach, bell peppers, watermelon, and strawberries provide plenty of water along with fiber, vitamins, minerals, and antioxidants. — Heather Jones, Verywell Health, 13 Aug. 2026

Extra virgin olive oil contains healthy fats to help maintain skin tone and antioxidants to reduce inflammation. — Lauren Jarvis-Gibson, Kansas City Star, 12 Aug. 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