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.
Honey has trace amounts of B vitamins, calcium, iron and some antioxidants. — Sheah Rarback, Miami Herald, 28 Aug. 2026 Thanks to a blend of peptides, biotin, green tea extract, amino acids, and antioxidants, expect strengthened, conditioned brows over time. — Iman Balagam, Vogue, 27 Aug. 2026 Cinnamon, rich in antioxidants, is known for fighting inflammation but has prompted questions about whether the spice has any other benefits beyond soothing. — Gavin Escott, USA Today, 27 Aug. 2026 Fiber-rich whole foods provide vitamins, minerals, antioxidants, and other plant compounds that candy generally lacks. — Amber Raiken, Verywell Health, 26 Aug. 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 1 Sep. 2026.

Copy Citation

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

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Popular in Grammar & Usage

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Is it 'nerve-racking' or 'nerve-wracking'?

What's the difference between 'fascism' and 'socialism'?

Why does English have so many silent letters?

7 Pairs of Commonly Confused Words
See More

Popular in Wordplay

See More

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of

Even More Words That Sound Like Insults But Aren't

Even More Bird Names that Sound Like Insults (and Sometimes Are)

12 Lovely and Unusual Words for the Natural World
See More

Popular

See More

A Who’s Who Regarding ‘Who’s’ and ‘Whose’

Ye Olde Nincompoop: Old-Fashioned Words for 'Stupid'

14 Phobias You Probably Haven't Heard Of
See More

Games & Quizzes

See All
Play Quordle: Guess all four words in a limited number of tries. Each of your guesses must be a real 5-letter word.
Quordle Can you solve 4 words at once?
Play Blossom: Solve today's spelling word game by finding as many words as you can using just 7 letters. Longer words score more points.
Blossom Pick the best words!
Play Missing Letter: a crossword with a twist. Each of the 25 puzzle words start with a different letter of the alphabet. Which letter is missing?
The Missing Letter A daily crossword with a twist
skateboard-dog-hat
Wordmaxxing Slang Quiz Give your vocabulary a glow up by getting sendy w...
See All