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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Following her cancer diagnosis, Isabella went through six weeks of radiation, four rounds of chemotherapy and three brain surgeries. Vanessa Etienne, People.com, 20 Nov. 2024 The technique, also known as solar radiation management, encompasses a range of technologies including sunshields in space, marine cloud brightening and stratospheric aerosol injection (SAI). Lara Williams, The Mercury News, 15 Nov. 2024 Solar flares are sudden, intense bursts of radiation from the sun's surface, typically as a result of magnetic energy that has built up in the solar atmosphere being suddenly released from sunspots or active regions. Thomas G. Moukawsher, Newsweek, 6 Nov. 2024 Like the ants in Them!, these creatures were often caused by radiation. Salama Udaipurwala, JSTOR Daily, 30 Oct. 2024 See all Example Sentences for radiation 

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 24 Nov. 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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