noun

antioxidant

an-tee-OK-sih-dunt

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Antioxidant (noun) means a substance that slows or prevents oxidation, the chemical reaction in which a molecule loses electrons, often to oxygen. In the body, antioxidants react with unstable molecules called free radicals; in food and cosmetics they are added to stop fats and other ingredients from going rancid or degrading. Example: “Vitamin E acts as an antioxidant in the formula and stops the oils turning.”

noun

A substance that slows or prevents oxidation, the chemical reaction in which a molecule loses electrons, often to oxygen. In the body, antioxidants react with unstable molecules called free radicals; in food and cosmetics they are added to stop fats and other ingredients from going rancid or degrading.

"Vitamin E acts as an antioxidant in the formula and stops the oils turning."

"The label listed an antioxidant among the preservatives."

adjective

Acting to prevent oxidation.

"antioxidant properties"

"The compound has an antioxidant effect in laboratory tests."

How to use antioxidant

Learner’s notes

In plain EnglishA substance that stops other things from reacting with oxygen and spoiling.

When to use it

Used across nutrition, food technology, chemistry and cosmetics; in food marketing the word is often used loosely.

Memory tip

The term describes what a substance does chemically, so the same word covers a vitamin, a plant extract and an industrial food additive.

Trace the full origin ↓

Easily confused with

oxidant preservative → polyphenol free radical

Common pairings

antioxidant properties dietary antioxidant antioxidant capacity rich in antioxidants

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C2 · Advanced serendipity Fortunate discoveries made entirely by accident.

Gen Z slang rizz Charm — the ability to attract a romantic interest.

B2 · Intermediate empathy The capacity to share another person’s feelings.

C1 · Advanced nonchalant Casually calm and relaxed; unconcerned.

Internet slang delulu Delusional — believing something against the odds.

Etymology nostalgia Greek nostos “return home” + algos “pain”.

C2 · Advanced serendipity Fortunate discoveries made entirely by accident.

Gen Z slang rizz Charm — the ability to attract a romantic interest.

B2 · Intermediate empathy The capacity to share another person’s feelings.

C1 · Advanced nonchalant Casually calm and relaxed; unconcerned.

Internet slang delulu Delusional — believing something against the odds.

Etymology nostalgia Greek nostos “return home” + algos “pain”.

Test yourself on “antioxidant” A quick quiz — meaning, synonyms & usage →

Fill the gap

Can you complete this real example?

Vitamin E acts as an _____ in the formula and stops the oils turning.

Etymology

From anti- meaning against, plus oxidant, a substance that causes oxidation.

Origin: English

Synonyms

View more →

free radical scavenger preservative stabiliser

Antonyms

oxidant pro-oxidant oxidising agent

Related words

preservative stabilizer

Rhymes for antioxidant

confidant

See all rhymes for antioxidant →

Frequently asked questions

What is a free radical?

It is a molecule with an unpaired electron, which makes it highly reactive and liable to take an electron from whatever it meets. Antioxidants are substances that can supply that electron without becoming unstable themselves.

Is antioxidant a category of nutrient?

Not exactly. It describes a chemical behaviour rather than a nutrient class. Vitamin C, vitamin E and many plant compounds are called antioxidants because of how they react, but they are otherwise unrelated substances with different roles.

Why are antioxidants added to cosmetics and foods?

To keep the product itself stable. Oils and certain active ingredients degrade on contact with air, and an antioxidant in the formula slows that process, extending shelf life.

What is the meaning of antioxidant?

"antioxidant" (noun) means a substance that slows or prevents oxidation, the chemical reaction in which a molecule loses electrons, often to oxygen. In the body, antioxidants react with unstable molecules called free radicals; in food and cosmetics they are added to stop fats and other ingredients from going rancid or degrading.

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