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

However, as antioxidants, the polyphenols in olive oil can neutralize those harmful molecules, thereby reducing oxidative stress and disease risk. —Kirsten Nunez, Martha Stewart, 10 Jan. 2026

This high-tech serum combines growth factors, antioxidants, and hydrating ingredients to smooth texture, even tone, and support the skin barrier. —Colleen Sullivan, InStyle, 10 Jan. 2026

While gummies are great for on-the-go convenience, greens powders are an excellent way to pack in all the good stuff—vitamins, antioxidants, adaptogens— into one tall glass of water. —Andrea Strong, Bon Appetit Magazine, 10 Jan. 2026

Berries Berries are rich in antioxidants, plant compounds that help reduce inflammation and protect cells from damage. —Carrie Madormo, Verywell Health, 9 Jan. 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