ir·​ra·​di·​ate | \ i-ˈrā-dē-ˌāt How to pronounce irradiate (audio) \
irradiated; irradiating

Definition of irradiate

transitive verb

1a : to affect or treat by radiant energy (such as heat) specifically : to treat by irradiation
b : to cast rays of light upon : illuminate
c : to enlighten intellectually or spiritually
2 : to emit like rays of light : radiate irradiating strength and comfort

intransitive verb

archaic : to emit rays : shine

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Other Words from irradiate

irradiative \ i-​ˈrā-​dē-​ˌā-​tiv How to pronounce irradiate (audio) \ adjective
irradiator \ i-​ˈrā-​dē-​ˌā-​tər How to pronounce irradiate (audio) \ noun

Synonyms & Antonyms for irradiate



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Examples of irradiate in a Sentence

The food was irradiated to kill any germs. the light from a galaxy of flashing signs irradiates the heart and soul of Las Vegas
Recent Examples on the Web The best time to irradiate, the two found, was 5.5 to 5.7 days into the pupal stage, when the adult fly’s ovaries and testes were developing and thus most sensitive to radiation. Sarah Zhang, The Atlantic, "The U.S. Is Spending Millions of Dollars Rearing Flesh-Eating Worms," 26 May 2020 Threatening to irradiate Mount Weather didn’t stop Cage, so Clarke and Bellamy actually did it. Alamin Yohannes,, "The 12 most twisted moments of The 100 (so far)," 20 May 2020 Many still mourn relatives who were kidnapped as infants and secretly given away for adoption, or died of cancer after being irradiated to treat ringworm upon arrival in Israel. David M. Halbfinger, New York Times, "Ace of Base: Why Netanyahu Seems Unsinkable," 3 Mar. 2020 Such fires are more dangerous around Chernobyl, as the trees and plant life are still irradiated from the 1986 nuclear disaster. NBC News, "Chernobyl radiation levels spike dramatically as forest fires burn in exclusion zone," 6 Apr. 2020 Milk & Milk Alternatives: Condensed, irradiated (aseptic) or powdered milk are important staples. Courtney Campbell, USA TODAY, "Everything you need at home if you are quarantined—and what you don’t," 12 Mar. 2020 Foods can also be irradiated to kill germs this way. Caroline Delbert, Popular Mechanics, "This Medical Device Is Loaded with Radioactive Raw Material," 30 Dec. 2019 Related Stories Not needing to irradiate U-238 might also be considered a plus. David Grossman, Popular Mechanics, "Andrew Yang Wants Thorium Nuclear Power. Here's What That Means.," 27 Aug. 2019 Utah feels like a breath of fresh air, like a bunch of light bulbs just went on, irradiating a path to the promise land. Sean Keeler, The Denver Post, "How Mel Tucker rebuilt the CU Buffs in his image," 24 Nov. 2019

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

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First Known Use of irradiate

1603, in the meaning defined at transitive sense 1b

History and Etymology for irradiate

Latin irradiatus, past participle of irradiare, from in- + radius ray

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Time Traveler for irradiate

Time Traveler

The first known use of irradiate was in 1603

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Statistics for irradiate

Cite this Entry

“Irradiate.” Dictionary, Merriam-Webster, Accessed 6 Mar. 2021.

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More Definitions for irradiate



English Language Learners Definition of irradiate

technical : to expose (someone or something) to radiation


ir·​ra·​di·​ate | \ i-ˈrā-dē-ˌāt How to pronounce irradiate (audio) \
irradiated; irradiating

Kids Definition of irradiate

1 : to cast rays of light on
2 : to treat by exposure to radiation (as X-rays)


transitive verb
ir·​ra·​di·​ate | \ ir-ˈād-ē-ˌāt How to pronounce irradiate (audio) \
irradiated; irradiating

Medical Definition of irradiate

: to affect or treat by radiant energy (as heat) specifically : to treat by exposure to radiation (as ultraviolet light or gamma rays)

More from Merriam-Webster on irradiate

Thesaurus: All synonyms and antonyms for irradiate

Nglish: Translation of irradiate for Spanish Speakers

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