Definition of "radiation" []

• The act or process of radiating: the radiation of heat and light from a fire. (noun)
• Physics Emission and propagation and emission of energy in the form of rays or waves. (noun)
• Physics Energy radiated or transmitted as rays, waves, in the form of particles. (noun)
• Physics A stream of particles or electromagnetic waves emitted by the atoms and molecules of a radioactive substance as a result of nuclear decay. (noun)
• The act of exposing or the condition of being exposed to such energy. (noun)

American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

• "The term radiation alone is used commonly for this type of energy, although it actually has a broader meaning. ... light of wave length 570 nm illuminates a diffraction grating. the second-order maximum is at angle 41.5 degre?"
• ""[A] Librarian told me that they were forced to take all the literature with the word 'radiation' and put it in [an] archive," Shapiro said."
• "But unless the radiation is at least a couple of orders of magnitude above background, the additional cancers due to radiation are indistinguishable among the cancers due to chemicals, foods, viruses, and ancestry."