radiation
noun
ra·di·a·tion
ˌrā-dē-ˈā-shən 
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
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 radiation oncologist Marisa Weiss, MD, breast cancer prevention is personal.
—
Anisa Arsenault, Health, 24 Oct. 2025
Instead of being dominated by matter and radiation, the Universe’s energy was inherent to space itself, leading to relentless, exponential expansion.
—Big Think, 24 Oct. 2025
Robots have become indispensable in environments where high radiation or structural complexity makes human intervention dangerous or impractical.
—Kaif Shaikh, Interesting Engineering, 24 Oct. 2025
One, initially released in 2016, claimed that cellphone radiation causes cancer based on findings from rats, though only male rats.
—ArsTechnica, 23 Oct. 2025
See All Example Sentences for radiation
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Anisa Arsenault, Health, 24 Oct. 2025
Instead of being dominated by matter and radiation, the Universe’s energy was inherent to space itself, leading to relentless, exponential expansion.
—Big Think, 24 Oct. 2025
Robots have become indispensable in environments where high radiation or structural complexity makes human intervention dangerous or impractical.
—Kaif Shaikh, Interesting Engineering, 24 Oct. 2025
One, initially released in 2016, claimed that cellphone radiation causes cancer based on findings from rats, though only male rats.
—ArsTechnica, 23 Oct. 2025
See All Example Sentences for radiation
Cite this Entry
“Radiation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radiation. Accessed 29 Oct. 2025.
Copy CitationKids Definition
radiation
noun
ra·di·a·tion
ˌrād-ē-ˈā-shən
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
Medical Definition
radiation
noun
ra·di·a·tion
ˌrād-ē-ˈā-shən
1
: energy radiated in the form of waves or particles
2
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
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