/ Dictionary / Index R radiator: Meaning and Definition of Find definitions for: ra•di•a•tor Pronunciation: (rā'dē-ā"tur), [key] — n. a person or thing that radiates. any of various heating devices, as a series or coil of pipes through which steam or hot water passes. a device constructed from thin-walled tubes and metal fins, used for cooling circulating water, as in an automobile engine. a transmitting antenna. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: radiator (Thesaurus) radiative capture radiator grille Related Content Daily Word Quiz: portent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language