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antioxidant

American  
[an-tee-ok-si-duhnt, an-tahy-] / ˌæn tiˈɒk sɪ dənt, ˌæn taɪ- /

noun

  • antioxidants
    plural
  1. Chemistry. any substance that inhibits oxidation, as a substance that inhibits oxidative deterioration of gasoline, rubbers, plastics, soaps, etc.

  2. Biochemistry. an enzyme or other organic substance, as vitamin E or beta carotene, that is capable of counteracting the damaging effects of oxidation in animal tissues.


adjective

  1. Chemistry. of or relating to an antioxidant.

antioxidant British  
/ ˌæntɪˈɒksɪdənt /

noun

  1. any substance that retards deterioration by oxidation, esp of fats, oils, foods, petroleum products, or rubber

  2. biology a substance, such as vitamin C, vitamin E, or beta carotene, that counteracts the damaging effects of oxidation in a living organism

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

antioxidant Scientific  
/ ăn′tē-ŏksĭ-dənt,ăn′tī- /
  1. A chemical compound or substance that inhibits oxidation. Certain vitamins, such as vitamin E, are antioxidants and may protect body cells from damage caused by the oxidative effects of free radicals.


Other Word Forms

Noun Inflected Forms

Etymology

Origin of antioxidant

First recorded in 1925–30; anti- + oxidant ( oxid(ize) + -ant )

Explanation

An antioxidant is a substance that helps prevent damage caused by certain chemical reactions in our bodies. Fruits, vegetables, and beans are full of antioxidants. Vitamins C and E are familiar antioxidants found in foods like spinach, strawberries, kiwifruit, and lima beans. These substances work in two main ways. They sometimes prevent chemical oxygen reactions that produce damaging, unstable free radicals. They can also bind with the free radicals to make them stable and keep them from causing damage. Antioxidants don't just protect our bodies; they are also used to keep food fresh — a squeeze of lemon juice (Vitamin C) on a sliced apple helps prevent oxidation that turns the fruit brown.

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Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

It is already known for its antioxidant and neuroprotective effects, and previous research has largely examined how it may benefit the body more broadly.

From Science Daily Jul. 30, 2026

Augustine Lee, a pulmonologist with the Mayo Clinic’s Jacksonville, Fla., campus, says a lifestyle and diet that promote antioxidant buildup is associated with less heart disease and cancer.

From The Wall Street Journal Jul. 23, 2026

Exercise also boosts antioxidant enzymes in the body, which protect cells from damage.

From The Wall Street Journal Jul. 23, 2026

The study also examined antioxidant compounds such as vitamin C, phenolics, and flavonoids.

From Science Daily May 23, 2026

“Just some antioxidant recipes. Ready for BiPAP and America’s Next Top Model?” she asked.

From "The Fault in Our Stars" by John Green

Coffee contains other substances that seem to be beneficial for health, too, the statement’s authors wrote, including polyphenols that may act as antioxidants and reduce inflammation.

From The Wall Street Journal Jul. 20, 2026

Instead, add a handful of berries, kiwis, or other fruits rich in fiber and antioxidants.

From MarketWatch Jun. 21, 2026

These antioxidants, found in certain foods, can support heart health, circulation and blood vessel elasticity by reducing inflammation, it says.

From BBC Jun. 8, 2026

Researchers say watermelon provides an impressive mix of nutrients, antioxidants, and naturally occurring compounds linked to cardiovascular and metabolic health.

From Science Daily May 17, 2026

Everything we sold was enriched with antioxidants or enhanced with natural super-fruit extracts or formulated for health and beauty.

From "Darius the Great Is Not Okay" by Adib Khorram

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