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

Antioxidant activity was measured using Trolox, a water-soluble analog of vitamin E that serves as a reference standard.

From Science Daily • Feb. 8, 2026

In my recipe for Super Antioxidant Blueberry Smoothie, I’ve combined them with pomegranate juice, yogurt and a little honey.

From Seattle Times • Jul. 1, 2023

Antioxidant levels inside tissues increase, protecting against damage caused by sudden changes in the amount of oxygen in cells.

From Science Magazine • Jun. 21, 2023

Antioxidant activity and composition of M&M's plain peanut candy.

From Salon • Jan. 22, 2023

I was interested in the benefits of chocolate and I said: "Antioxidant."

From "Counting by 7s" by Holly Goldberg Sloan