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

Red and green grapes both contain antioxidants and have anti-inflammatory properties. —Heather Jones, Verywell Health, 14 Nov. 2025

Eat More Avocado Avocados contain good fat, vitamins, minerals, antioxidants, and fiber. —Cynthia Sass, Health, 14 Nov. 2025

For example, adding fruit, nuts or yogurt introduces additional vitamins, antioxidants, healthy fats and extra protein. —Daryl Austin, USA Today, 14 Nov. 2025

Lemons are high in vitamin C, help with digestion, and are full of antioxidants. —Cameron Beall, Southern Living, 12 Nov. 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