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

4

: adaptive radiation

radiational

ˌrā-dē-ˈā-shnəl 

-shə-nᵊl

adjective

radiationless

ˌrā-dē-ˈā-shən-ləs 

adjective

radiative

ˈrā-dē-ˌā-tiv 

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

Additional time off was needed for working cancer patients to get hospital care, undergo surgery or visit specialists such as radiation oncologists. —Ken Alltucker, USA TODAY, 23 Apr. 2024

Solar radiation modification — a form of geoengineering designed to artificially cool the planet — is also being seriously studied as a solution. —Hayley Smith, Los Angeles Times, 22 Apr. 2024

Some question if putting oneself up for voluntary exposure to radiation from these types of scans can, itself, cause issues. —Max Berlinger, Robb Report, 18 Apr. 2024

Treatment includes surgery, radiation, chemotherapy or different forms of therapy such as electric field therapy, which uses electrical fields to target cells in the tumor while not hurting normal cells, according to WebMD. —Minyvonne Burke, NBC News, 17 Apr. 2024

Sunglasses should block 99% to 100% of UVA and UVB radiation to prevent long-term exposure to sunlight. —Staff Author, Parents, 13 Apr. 2024

Mike’s mother was also about to start radiation for stage 0 breast cancer. —Alexis Berger, SELF, 11 Apr. 2024

The sun heats up the dark rock, which absorbs solar radiation more easily because of its color, which melts the surrounding ice. —Katie Hunt, CNN, 10 Apr. 2024

In addition to the electromagnetic radiation from the sun's corona, there's another form of radiation traveling from the sun to the Earth, the space agency explained. —Aliza Chasan, CBS News, 8 Apr. 2024

Word History

First Known Use

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

Phrases Containing radiation

• adaptive radiation
• anti-radiation
• background radiation
• Cerenkov radiation
• cosmic background radiation
• electromagnetic radiation
• gamma radiation
• gravitational radiation
• radiation sickness
• radiation therapy
• secondary radiation
• synchrotron radiation
• x-radiation

Kids 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

radiational

-shnəl 

-shən-ᵊl

adjective

Medical Definition

radiation

noun

ra·​di·​a·​tion ˌrād-ē-ˈā-shən 

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 nerve

—J. 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