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

The compound also acts as a potent antioxidant, neutralizing unstable molecules that build up in non-healing wounds and cause cellular damage. — Abhimanyu Ghoshal, New Atlas, 7 Oct. 2026

Four types of hyaluronic acid plump skin and counteract potential dryness, while collagen amino acids and antioxidants help protect skin’s natural collagen for a firmer, smoother look. — Christa Joanna Lee, Allure, 7 Oct. 2026

Even a blueberry muffin, with the fiber, antioxidants and other good stuff that comes from blueberries, usually has more fat, sugar and calories than a slice of blueberry pie. — CBS News, 7 Oct. 2026

Glyphosate and phthalates Although cats are carnivores, many manufacturers add produce to cat food for its antioxidants, minerals and vitamins. — Sandee Lamotte, CNN Money, 2 Oct. 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