/ Dictionary / Index R radiation: Meaning and Definition of Find definitions for: ra•di•a•tion Pronunciation: (rā"dē-ā'shun), [key] — n. 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. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: radiation (Thesaurus) radiate radiation belt Related Content Daily Word Quiz: modify Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language