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

Walnuts Walnuts stand out among nuts for their exceptionally high levels of polyphenols (plant compounds) and vitamin E, antioxidants that protect fats within the body from harmful oxidation. —Lauren Panoff, Verywell Health, 30 Oct. 2025

The soothing, antioxidant-rich formula offers enough coverage that it can be used in lieu of a tinted moisturizer or lightweight foundation. —Emily Orofino, Vogue, 30 Oct. 2025

Seriously though, collard greens contain a ton of Vitamin K, as well as plenty of antioxidants. —Josh Miller, Southern Living, 30 Oct. 2025

Provides Antioxidants Corn—especially colorful varieties like yellow, blue, or purple—is rich in antioxidants. —Lindsey Desoto, Health, 30 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