antioxidant

noun

an·​ti·​ox·​i·​dant ˌan-tē-ˈäk-sə-dənt How to pronounce antioxidant (audio)
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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Among the antioxidants in pomegranates, Syn notes, are polyphenols called anthocyanins, which give the fruit its deep red color. — Daryl Austin, USA Today, 2 July 2026 Yellow watermelon has a high water content and contains beta-carotene (the same antioxidant that gives carrots their orange hue). — Christine Fiorentino, Better Homes & Gardens, 30 June 2026 Wild blueberries and strawberries also lend extra fiber, vitamins, minerals, and antioxidants, Mok adds. — Randi Gollin, Martha Stewart, 1 July 2026 Even if cherries aren’t your thing, there are plenty of other fruits that provide anti-inflammatory benefits and can even help your gut thanks to the presence of powerful antioxidants (like polyphenols and vitamin C) and fiber. — Laura Solla, Vogue, 1 July 2026 See All Example Sentences for antioxidant

Word History

First Known Use

1919, in the meaning defined above

Time Traveler
The first known use of antioxidant was in 1919

Rhymes for antioxidant

See All Rhymes for antioxidant

Browse Nearby Words

anti-organization
antioxidant
antioxygen
See all Nearby Words

Cite this Entry

“Antioxidant.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/antioxidant. Accessed 7 Jul. 2026.

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Kids Definition

antioxidant

noun
an·​ti·​ox·​i·​dant ˌant-ē-ˈäk-səd-ənt How to pronounce antioxidant (audio)
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- How to pronounce antioxidant (audio)
: 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

More from Merriam-Webster on antioxidant

Britannica.com: Encyclopedia article about antioxidant

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