/ Dictionary / Index R radar: Meaning and Definition of Find definitions for: ra•dar Pronunciation: (rā'där), [key] — n. Electronics. a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: radar (Thesaurus) rad radar astronomy Related Content Daily Word Quiz: braggart Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language