antioxidant

American  

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

noun

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.

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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

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antioxidant Scientific  

/ ăn′tē-ŏk′sĭ-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.

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Etymology

Origin of antioxidant

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

Example Sentences

The study found that excessive antioxidant intake can alter sperm DNA and may increase the likelihood of developmental differences in offspring, particularly in facial and skull formation.

From Science Daily • Mar. 27, 2026

That’s on top of the injections Leite gives herself regularly: NAD+, which she says makes her feel energized and alleviates her brain fog, and glutathione, which is marketed for antioxidant and immune support.

From The Wall Street Journal • Mar. 18, 2026

They increase levels of "reactive oxygen species," unstable molecules that can damage cells, while also weakening the body's antioxidant defenses that normally keep these molecules under control.

From Science Daily • Mar. 13, 2026

These components may help enhance antioxidant activity in the body and reduce lipid oxidation, a process associated with oxidative stress.

From Science Daily • Feb. 22, 2026

After a minute, Mom said, “I’m taking some classes. Online, through IU. To get my master’s in social work. In fact, I wasn’t looking at antioxidant recipes; I was writing a paper.”

From "The Fault in Our Stars" by John Green