free radical

noun

Definition of free radical 

: 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

Much like the sun causes skin cancer, the damage from UV rays can cause the creation of destructive molecules within the body, called free radicals, Khan explains. Macaela Mackenzie, Allure, "The Scary Way Blue Light From Your Phone Can Affect Your Eyes and Vision," 6 July 2018 Research published in the Journal of Nutrition found that a zinc deficiency in rats led to impairments in DNA repair caused by free radicals, which can speed the aging process. Amy Capetta, Woman's Day, "5 Anti-Aging Supplements That May Actually Work," 16 Oct. 2018 Like other berries, açaí are packed with antioxidants that can help build up your immune system and protect your cells against damage from free radicals. Tehrene Firman, Good Housekeeping, "10 Things You Should Know About Açaí Berries, Nature's "Purple Gold"," 23 July 2018 Antioxidants are responsible for keeping your body and skin protected from harmful free radicals — unstable molecules that can cause your skin to age faster and potentially lead to skin cancer and other health issues. Dr. Leslie Baumann, miamiherald, "Five antioxidant-rich foods to pile on your plate for better skin | Miami Herald," 2 Apr. 2018 During the process, free radicals and singlet oxygen are also formed and can inflict damage on cellular membranes, organelles, and proteins. Lindsey Murray, Good Housekeeping, "[UPDATED] Woman Claims She Received Horrific Burns After Using Essential Oils," 28 Apr. 2017 Tim Calver © Tim Calver Bleaching occurs when water temperatures rise and the algae that live inside the coral, which photosynthesize and produce food for the corals, instead produce free radicals that are toxic, Baker said. Jenny Staletovich, miamiherald, "Reefs are dying. Miami scientists hope lab-bred ‘super corals’ can help revive them | Miami Herald," 2 Mar. 2018 Alcohol creates free radicals and ups inflammation. Krista Bennett Demaio, Cosmopolitan, "9 Beauty Fails That Mess With Your Skin (and How to Fix Them)," 2 Jan. 2015 Inflammation throughout your body turns on enzymes that break down collagen and leads to the production of free radicals, which can damage cells. Dr. Melina Jampolis, CNN, "Aging gracefully: Tightening your skin safely and effectively," 16 May 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'free radical.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

See More

First Known Use of free radical

1870, in the meaning defined above

Keep scrolling for more

Learn More about free radical

Share free radical

Dictionary Entries near free radical

free port

Freeport

freer

free radical

free-range

free rate

free reach

Statistics for free radical

Last Updated

2 Dec 2018

Look-up Popularity

Time Traveler for free radical

The first known use of free radical was in 1870

See more words from the same year

Keep scrolling for more

More Definitions for free radical

free radical

noun

Medical Definition of free radical 

: 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

More from Merriam-Webster on free radical

Britannica.com: Encyclopedia article about free radical

Comments on free radical

What made you want to look up free radical? Please tell us where you read or heard it (including the quote, if possible).

WORD OF THE DAY

a nest or breeding place

Get Word of the Day daily email!

Test Your Vocabulary

Late Autumn 2018 Words of the Day Quiz

  • frosted-autumn-leaves
  • Which is a synonym of yahoo?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

TAKE THE QUIZ
Bee Cubed

Test Your Knowledge - and learn some interesting things along the way.

TAKE THE QUIZ

Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!