radiation

noun
ra·​di·​a·​tion | \ ˌrā-dē-ˈā-shən How to pronounce radiation (audio) \

Definition of radiation

1a : the action or process of radiating
b : the process of emitting radiant energy in the form of waves or particles
c(1) : the combined processes of emission, transmission, and absorption of radiant energy
(2) : the transfer of heat by radiation — compare conduction, convection
2a : something that is radiated
b : energy radiated in the form of waves or particles
3 : radial arrangement

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Other Words from radiation

radiational \ ˌrā-​dē-​ˈā-​shnəl How to pronounce radiation (audio) , -​shə-​nᵊl \ adjective
radiationless \ ˌrā-​dē-​ˈā-​shən-​ləs How to pronounce radiation (audio) \ adjective
radiative \ ˈrā-​dē-​ˌā-​tiv How to pronounce radiation (audio) \ adjective

Examples of radiation in a Sentence

She was exposed to high levels of radiation. He goes in for radiation next week. the sun's radiation of heat
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Recent Examples on the Web Explanations from folks in Emmonak include: climate change, species encroachment, foreign ghost fleets, trawlers, Fukushima radiation, bycatch and international hatcheries. Zachariah Hughes, Anchorage Daily News, 7 Sep. 2021 This magnetic field helps protect the Earth from being bombarded by solar winds and cosmic radiation. Caroline Delbert, Popular Mechanics, 3 Sep. 2021 The tiny squishy organisms can survive harsh stressors like freezing temperatures, lethal doses of radiation, dehydration and even impact speeds of up to 1,845 miles per hour. Elizabeth Gamillo, Smithsonian Magazine, 3 Sep. 2021 During the fires, Schladow’s team is taking measurements every few days, venturing out on the water to collect water samples and measure UV radiation, water clarity, nutrients and algae. Rachel Becker, San Francisco Chronicle, 1 Sep. 2021 The family said Allen fought her cancer through six cycles of chemotherapy, a double mastectomy and reconstruction, lymph node removal and five weeks of daily radiation. Jeff Truesdell, PEOPLE.com, 24 Aug. 2021 The need to suppress radiation from the particle speaks to a subtle yet critical issue. Quanta Magazine, 18 Aug. 2021 These could be areas impacted by war, radiation, economics, or climate. Deboki Chakravarti, Scientific American, 27 Aug. 2021 Val Kilmer's passion for expressing himself creatively has never wavered, even after battling throat cancer in 2015 which required chemotherapy, radiation and a tracheostomy that damaged his vocal cords and permanently altered his speaking voice. Kara Warner, PEOPLE.com, 26 Aug. 2021

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radiation.' 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 radiation

15th century, in the meaning defined at sense 1a

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Time Traveler for radiation

Time Traveler

The first known use of radiation was in the 15th century

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Dictionary Entries Near radiation

radiateness

radiation

radiation belt

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Statistics for radiation

Last Updated

10 Sep 2021

Cite this Entry

“Radiation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radiation. Accessed 20 Sep. 2021.

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More Definitions for radiation

radiation

noun

English Language Learners Definition of radiation

: a type of dangerous and powerful energy that is produced by radioactive substances and nuclear reactions
: the use of controlled amounts of radiation for the treatment of diseases (such as cancer)
: energy that comes from a source in the form of waves or rays you cannot see

radiation

noun
ra·​di·​a·​tion | \ ˌrā-dē-ˈā-shən How to pronounce radiation (audio) \

Kids Definition of radiation

1 : the process of giving off energy in the form of waves or particles
2 : something that is radiated (as light or X-rays)

radiation

noun
ra·​di·​a·​tion | \ ˌrād-ē-ˈā-shən How to pronounce radiation (audio) \

Medical Definition of radiation

1 : energy radiated in the form of waves or particles
2a : the action or process of radiating with radiation of the pain there may be tenderness over the sciatic nerve— J. A. Key
b(1) : the process of emitting radiant energy in the form of waves or particles
(2) : the combined processes of emission, transmission, and absorption of radiant energy
3 : a tract of nerve fibers within the brain especially : one concerned with the distribution of impulses arising from sensory stimuli to the relevant coordinating centers and nuclei the optic radiations

More from Merriam-Webster on radiation

Nglish: Translation of radiation for Spanish Speakers

Britannica English: Translation of radiation for Arabic Speakers

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