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

Made with prebiotic oat to soothe irritation and support the skin barrier, the gentle cream also has feverfew extract, which is packed with antioxidants that reduce redness and further calm irritation. —Jenny Berg, Vogue, 4 Sep. 2025

Certain cancers The antioxidants in oranges and orange juice may have properties that lower inflammatory markers in the body. —Carrie Madormo, Verywell Health, 4 Sep. 2025

Whole foods rich in natural color are packed with the vitamins and antioxidants growing bodies need. —Jazmine A. Ortiz, USA Today, 3 Sep. 2025

The outer shell is the bran that contains antioxidants, B vitamins and fiber. —Sheah Rarback, Miami Herald, 3 Sep. 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