radiation

[ rey-dee-ey-shuh n ]

/ ˌreɪ diˈeɪ ʃən /

SEE MORE SYNONYMS FOR radiation ON THESAURUS.COM

noun

Physics.

the process in which energy is emitted as particles or waves.
the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and absorbed by another body.
the energy transferred by these processes.

the act or process of radiating.

something that is radiated.

radial arrangement of parts.

Nearby words

radiata, radiata pine, radiate, radiate crown, radiate ligament of rib, radiation, radiation belt, radiation biology, radiation damage, radiation dermatitis, radiation fog

Origin of radiation

1545–55; < Latin radiātiōn- (stem of radiātiō) a glittering, shining. See radiate, -ion

Related forms

ra·di·a·tion·al, adjectivean·ti·ra·di·a·tion, adjectivein·ter·ra·di·a·tion, nounnon·ra·di·a·tion, noun

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for radiation

He was very familiar with the reality of what could happen: Tokyo could be covered with a really high dosage of radiation.
Takashi Murakami’s Art From Disaster|Justin Jones|November 28, 2014|DAILY BEAST
Everything serene, snow piling on trees, over lawns, on houses, before we realize that all the snow is poisoned with radiation.
The Internet Embedded in Your Head|J.T. Price|November 21, 2014|DAILY BEAST
The 4M craft also includes a radiation dosimeter built by the Spanish company iC-Málaga.
Luxembourg and China Team Up on Private Mission to the Moon|Matthew R. Francis|October 26, 2014|DAILY BEAST
She said that whenever she came into the room, she had felt the radiation of a vast and unseen force.
Those Kansas City Blues: A Family History|Katie Baker|October 24, 2014|DAILY BEAST

Those Chinese reports also talked about radiation deaths in Chicago.
Putin Threatens Nuclear War Over Ukraine|Gordon G. Chang|August 31, 2014|DAILY BEAST
Attention is here drawn once more to the antagonistic reactions of temperature and radiation effects of heat.
Life Movements in Plants|Sir Jagadis Chunder Bose
There is also a significant amount of radiation characteristic of uranexite.
Masters of Space|Edward Elmer Smith
Rip watched his dosimeter climb steadily as the radiation dosage mounted.
Rip Foster in Ride the Gray Planet|Harold Leland Goodwin
Symptoms of radiation sickness may not be noticed for several days.
In Time Of Emergency|Department of Defense
The worst wounded had less than half a face, and that discolored by purple blotches of radiation scar-tissue.
Mr. President|Stephen Arr

British Dictionary definitions for radiation

radiation

/ (ˌreɪdɪˈeɪʃən) /

noun

physics

the emission or transfer of radiant energy as particles, electromagnetic waves, sound, etc
the particles, etc, emitted, esp the particles and gamma rays emitted in nuclear decay

Also called: radiation therapy med treatment using a radioactive substance

anatomy a group of nerve fibres that diverge from their common source

See adaptive radiation

the act, state, or process of radiating or being radiated

surveying the fixing of points around a central plane table by using an alidade and measuring tape

Derived Forms

radiational, adjective

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Medicine definitions for radiation

radiation

[ rā′dē-ā′shən ]

n.

The act or condition of diverging in all directions from a center.

The emission and propagation of energy in the form of rays or waves.

The energy radiated or transmitted in the form of rays, waves, or particles.

A stream of particles or electromagnetic waves that is emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay.

Radiotherapy.

The radial arrangement of anatomical or histological parts.

The spread of a group of organisms into new habitats.

Science definitions for radiation

radiation

[ rā′dē-ā′shən ]

Streams of photons, electrons, small nuclei, or other particles. Radiation is given off by a wide variety of processes, such as thermal activity, nuclear reactions (as in fission), and by radioactive decay.
The emission or movement of such particles through space or a medium, such as air. See Notes at conduction electromagnetic radiation.

The use of such energy, especially x-rays, in medical diagnosis and treatment.

Culture definitions for radiation

radiation

Energy sent out in the form of particles or waves. (See alpha radiation, beta radiation, blackbody, cosmic rays, electromagnetic radiation, fluorescence, gamma radiation, photon, and quanta.)