antioxidant

noun

an·​ti·​ox·​i·​dant ˌan-tē-ˈäk-sə-dənt 

ˌan-ˌtī-

: a substance (such as beta-carotene or vitamin C) that inhibits oxidation or reactions promoted by oxygen, peroxides, or free radicals

antioxidant adjective

Examples of antioxidant in a Sentence

Recent Examples on the Web

The glossy, non-sticky formula combines nourishing sunflower and jojoba seed oils with antioxidant-rich acerola fruit extract and a peptide blend to help lips feel softer, smoother, and a little plumper-looking, all while leaving behind a juicy wash of tint and shine. —Christa Joanna Lee, Allure, 20 May 2026

The nontoxic, antioxidant-rich lip oils are made with calming botanicals to deliver soft, plump, hydrated lips. —ABC News, 19 May 2026

Cabbage and cauliflower both support heart health with fiber, antioxidants, and plant compounds. —Lindsey Desoto, Health, 19 May 2026

Improves Heart Health Oats are rich in unique antioxidants called avenanthramides, which are not found in other cereals. —Lana Barhum, Verywell Health, 18 May 2026

Word History

First Known Use

1919, in the meaning defined above

Rhymes for antioxidant

• oxidant

Kids Definition

antioxidant

noun

an·​ti·​ox·​i·​dant ˌant-ē-ˈäk-səd-ənt 

ˌan-ˌtī-

: a substance that opposes oxidation or prevents or makes difficult reactions made easier by oxygen

Medical Definition

antioxidant

noun

an·​ti·​ox·​i·​dant ˌant-ē-ˈäk-səd-ənt, ˌan-ˌtī- 

: any of various substances (as beta-carotene, vitamin C, and alpha-tocopherol) that inhibit oxidation or reactions promoted by oxygen and peroxides and that include many held to protect the living body from the deleterious effects of free radicals

antioxidant adjective