free radical

noun

: an especially reactive atom or group of atoms that has one or more unpaired electrons

especially : one that is produced in the body by natural biological processes or introduced from an outside source (such as tobacco smoke, toxins, or pollutants) and that can damage cells, proteins, and DNA by altering their chemical structure

Examples of free radical in a Sentence

Recent Examples on the Web

Studies have shown that antioxidants play a key role in fighting cellular damage caused by free radicals, which helps to reduce inflammation, promote a strong immune system, and lower the risk of developing heart disease and cancer. —Caroline C. Boyle, USA TODAY, 12 Sep. 2024

This two-time Best of Beauty Award winner deserves applause for its effective blend of 10% stabilized vitamin C and ferulic acid (similar to C E Ferulic) that brightens and protects skin from free radicals. —Sarah Han, Allure, 10 Sep. 2024

Dandelions can protect the body from free radicals that may damage healthy cells. —Devineé Lingo, M.s., Rdn, Health, 9 Sep. 2024

Prickly pear and white sage extract in the formula additionally help protect skin from blue light and free radicals, respectively. —Danielle Sinay, Glamour, 13 Aug. 2024

Word History

First Known Use

1870, in the meaning defined above

Medical Definition

free radical

noun

: an especially reactive atom or group of atoms that has one or more unpaired electrons

especially : one that is produced in the body by natural biological processes or introduced from outside (as in tobacco smoke, toxins, or pollutants) and that can damage cells, proteins, and DNA by altering their chemical structure