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

In addition, these seeds are high in fiber, antioxidants, and anti-inflammatory omega-3 fatty acids. —Cristina Mutchler, Verywell Health, 1 Apr. 2026

The matcha gives the mask a natural, earthy smell, a boost of antioxidants, and a faint green hue. —Alaina Chou, Bon Appetit Magazine, 1 Apr. 2026

Green tea is full of antioxidants, which are compounds that help protect your cells from damage and can lower your risk for disease. —Merve Ceylan, Health, 31 Mar. 2026

The formula includes soothing hydrators such as glycerin, dimethicone, and glyceryl behenate, plus antioxidants (vitamin E and C derivatives) to help calm and protect the skin. —Lauren Jarvis-Gibson, Miami Herald, 30 Mar. 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