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

---

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.

---

Other Word Forms

Noun Inflected Forms

• antioxidants
  plural

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.

Example Sentences

A 2025 Scientific Reports study in rats found that a nitrate and antioxidant mouth rinse supported nitrate and nitrite reducing oral bacteria and was associated with lower blood pressure compared with chlorhexidine treatment.

From Science Daily • May 25, 2026

Their study, published in Tropical Plants, found that the cooler temperature slows ripening, preserves fruit structure, and activates the mango's natural antioxidant defenses.

From Science Daily • May 23, 2026

Protective antioxidant enzymes remained more active for longer periods in mangoes stored at 12°C.

From Science Daily • May 23, 2026

By boosting the expression of a gene linked to tRNA, the team increased levels of anthocyanins and terpenoids, compounds that contribute to color, aroma, and antioxidant properties.

From Science Daily • May 5, 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