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
With Homelander’s powers removed, thanks to Kimiko (Karen Fukuhara) blasting him with radiation, Butcher gains the upper hand and stabs Homelander through the brain with a crowbar.
—
Jordan Moreau, Variety, 20 May 2026
The whole radiation trick from last week also feels like a classic case of deus ex machina, introduced way too late to work narratively.
—Ben Rosenstock, Vulture, 20 May 2026
This radiation is too weak to knock electrons out of atoms, a process called ionization that can harm tissue and DNA.
—Matt Fuchs, Time, 20 May 2026
The radiation doctors are burning you.
—Eileen Finan, PEOPLE, 19 May 2026
See All Example Sentences for radiation
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Jordan Moreau, Variety, 20 May 2026
The whole radiation trick from last week also feels like a classic case of deus ex machina, introduced way too late to work narratively.
—Ben Rosenstock, Vulture, 20 May 2026
This radiation is too weak to knock electrons out of atoms, a process called ionization that can harm tissue and DNA.
—Matt Fuchs, Time, 20 May 2026
The radiation doctors are burning you.
—Eileen Finan, PEOPLE, 19 May 2026
See All Example Sentences for radiation
Cite this Entry
“Radiation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radiation. Accessed 21 May. 2026.
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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