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

Spinach is a leafy green vegetable that is low in calories and high in vitamins, minerals, and antioxidants. —Lana Barhum, Verywell Health, 5 Dec. 2025

According to Ussery, raspberries are rich in vitamin C and polyphenols, a type of antioxidant. —Sherri Gordon, Health, 5 Dec. 2025

The antioxidants and anti-inflammatory properties of walnuts have also been shown to improve brain function and slow cognitive decline associated with aging. —Sara Moniuszko, USA Today, 4 Dec. 2025

Studies show that heating tomatoes releases more lycopene, the powerful antioxidant associated with cell protection and anti-inflammatory effects. —Desireé Oostland, Vogue, 4 Dec. 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