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

Avocado Avocados contain lutein, an antioxidant important for brain health. —Sarah Garone, Health, 15 Apr. 2026

Frozen Vegetables Frozen vegetables are picked at peak ripeness and flash-frozen, locking in vitamins, minerals, and antioxidants. —Morgan Pearson, Verywell Health, 15 Apr. 2026

Its silky smooth gel formula turns into a refreshing foam when mixed with water, washing away makeup, dirt, and bacteria with the help of prebiotics and antioxidants. —Averi Baudler, PEOPLE, 15 Apr. 2026

Similar to salmon, turmeric is also rich in anti-inflammatory compounds—specifically, an antioxidant known as curcumin. —Caroline Tien, SELF, 9 Apr. 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