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

Chia seeds are packed with nutrients, offering fiber, protein, omega-3s, and antioxidants. —Heather Jones, Verywell Health, 10 Oct. 2025

Mechanical processes used to produce extra virgin olive oil preserve its natural antioxidant content. —Merve Ceylan, Health, 10 Oct. 2025

Real fiber, antioxidants, and stable energy. —Dr. Sanjay Bhojraj, CNBC, 10 Oct. 2025

With help from melon antioxidants, peptides, and SPF, the hydrating product shields your skin from harmful rays while also minimizing fine lines. —Izzy Baskette, PEOPLE, 8 Oct. 2025

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