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 For the Fire Department, the list included kits to treat patients who are having heart emergencies, extrication equipment that can be used in crowded areas and monitors for chemical threats and radiation. Alison Dirr, Journal Sentinel, 7 Mar. 2024 Related article Gene that protected humans 5,000 years ago may be linked to debilitating modern disease The shower of radiation as cosmic rays interact with the atmosphere can penetrate rock, creating cosmogenic nuclides, or isotopes. Katie Hunt, CNN, 6 Mar. 2024 The military also spread radioactive sand across a simulated American town to track the movement of contamination and conducted radiation experiments on sheep and cows to appalling effect. John Metcalfe, The Mercury News, 26 Feb. 2024 Big data, and innovation in analytics, enable us to measure inputs from satellites, sensors and weather monitoring stations to predict solar radiation and wind speed, accurately forecasting the supply of renewable energy generation. Sumant Sinha, Forbes, 26 Feb. 2024 Since then, Doherty — who underwent brain surgery and radiation in January of 2023 — been open about her health journey. Cara Lynn Shultz, Peoplemag, 26 Feb. 2024 Over the past five years, she’s been in and out of the hospital for radiation, chemotherapy, surgeries and hormone therapy, as the cancer spread to her liver, lymph nodes, spine and bones. Sophia Liang, The Courier-Journal, 23 Feb. 2024 Previous observations had shown no water at all—which was unsurprising, given that water would be hard-pressed to survive the intense radiation so close to the star. Shannon Hall, Scientific American, 23 Feb. 2024 Plus, beta radiation isn't as harmful as, say, gamma rays. Rhett Allain, WIRED, 23 Feb. 2024

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 18 Mar. 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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