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

Antioxidant-rich foods play a major part in calming inflammation, neutralizing free radicals and suppressing the body’s pro-inflammatory processes for a more harmonic immune response. —Calin Van Paris, Vogue, 18 June 2024

Citrus peels also possess antioxidants that help fight free radicals, reduce the risk of chronic diseases, and boost skin health. —Nick Blackmer, Verywell Health, 12 June 2024

Walnuts are high in antioxidants which battle free radicals that destroy cells. —Bryant Stamford, The Courier-Journal, 6 June 2024

Running long distances or at a high intensity can create free radicals, or substances that damage cells.10 Foods that are rich in antioxidants and other nutrients can neutralize these harmful chemicals. —Laurel Leicht, Health, 1 June 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