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.

---

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.

---

Etymology

Origin of antioxidant

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

Example Sentences

"Creatine's anti-inflammatory and antioxidant properties further underscore its promise in clinical settings, though more robust trials are needed to confirm these benefits," he explains.

From Science Daily • May 4, 2026

"If you're taking a high dose antioxidant, you could be diminishing your reproductive fitness and part of the journey toward the bad outcome is going to be the effects on the offspring."

From Science Daily • Mar. 27, 2026

Previous studies have already shown that very high antioxidant intake can have drawbacks.

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

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