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definitions

radiation

[rey-dee-ey-shuh n]
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SEE MORE SYNONYMS FOR radiation ON THESAURUS.COM

noun

Physics.
  1. the process in which energy is emitted as particles or waves.
  2. the complete process in which energy is emitted by one body, transmitted through an intervening medium or space, and absorbed by another body.
  3. the energy transferred by these processes.
the act or process of radiating.
something that is radiated.
radial arrangement of parts.

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RELATED WORDS

emission, radioactivity, diffusion, circulation, transmission, divergence, broadcast, dispersion, propagation, spread, ramification, dispersal, dissipation, distribution, scattering, divarication, polarization, diffraction

Origin of radiation

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

Contemporary Examples of radiation

Historical Examples of radiation

  • Perhaps the tape was fuzzy or it may have been fogged in transit by radiation.

    Mezzerow Loves Company

    Floyd L. Wallace

  • "Here's the source of radiation, sir," a searchman reported.

    Masters of Space

    Edward Elmer Smith

  • There is also a significant amount of radiation characteristic of uranexite.

    Masters of Space

    Edward Elmer Smith

  • The radiation of a star is different for different wave-lengths (λ).

    Lectures on Stellar Statistics

    Carl Vilhelm Ludvig Charlier

  • The apparent attributes of the stars are studied by the aid of their radiation.

    Lectures on Stellar Statistics

    Carl Vilhelm Ludvig Charlier

British Dictionary definitions for radiation

radiation

noun

physics
  1. the emission or transfer of radiant energy as particles, electromagnetic waves, sound, etc
  2. 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 Formsradiational, 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
Word Origin and History for radiation
n.

mid-15c., "act or process of radiating," from Middle French radiation and directly from Latin radiationem (nominative radiatio) "a shining, radiation," noun of action from past participle stem of radiare "to beam, shine, gleam; make beaming," from radius "beam of light; spoke of a wheel" (see radius). Meaning "rays or beams emitted" is from 1560s. Meaning "divergence from a center" is 1650s.

Online Etymology Dictionary, © 2010 Douglas Harper
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.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.
Science definitions for radiation

radiation

[rā′dē-ā′shən]

  1. 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.
  2. 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.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
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.)

The New Dictionary of Cultural Literacy, Third Edition Copyright © 2005 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.