radiation

noun

ra·​di·​a·​tion ˌrā-dē-ˈā-shən How to pronounce radiation (audio)
1
a
: 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
2
a
: something that is radiated
b
: energy radiated in the form of waves or particles
3
: radial arrangement
4
radiational adjective
radiationless adjective
radiative 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
Recent Examples on the Web This maximum is due to the amount of torque on the black hole generated by radiation emitted from the accretion disk and swallowed by the black hole. Isaac Schultz / Gizmodo, Quartz, 23 May 2024 Lethal levels of radiation threaten to fry any interloper. Shi En Kim, Smithsonian Magazine, 22 May 2024 One of those women, by the way, is his own mother, Elizabeth Butker, a medical physicist in the department of radiation oncology at Emory University. Greg Cote, Miami Herald, 19 May 2024 The explosive burst of radiation is the largest solar flare detected since 2017, and is by far the biggest of the sun's 11-year solar cycle, according to the National Oceanic and Atmospheric Administration. Eric Lagatta, USA TODAY, 15 May 2024 See all Example Sentences for radiation 

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'radiation.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

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

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

Dictionary Entries Near radiation

Cite this Entry

“Radiation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radiation. Accessed 14 Jun. 2024.

Kids Definition

radiation

noun
ra·​di·​a·​tion ˌrād-ē-ˈā-shən How to pronounce radiation (audio)
1
: the action or process of radiating
especially : the process of giving off radiant energy in the form of waves or particles
2
: something that is radiated
especially : energy radiated in the form of waves or particles
radiational
-shnəl How to pronounce radiation (audio)
-shən-ᵊl
adjective

Medical Definition

radiation

noun
ra·​di·​a·​tion ˌrād-ē-ˈā-shən How to pronounce radiation (audio)
1
: energy radiated in the form of waves or particles
2
a
: the action or process of radiating
with radiation of the pain there may be tenderness over the sciatic nerveJ. 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

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