See more synonyms for radar on Thesaurus.com
  1. 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.
  2. a means or sense of awareness or perception: lobbyists working under the media's radar.

Origin of radar

1940–45, Americanism; ra(dio) d(etecting) a(nd) r(anging)
Related formsan·ti·ra·dar, noun, adjective
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Related Words for radar


Examples from the Web for radar

Contemporary Examples of radar

Historical Examples of radar

  • Alright, Mr. Stewart, how did you find your cow, with some new kind of radar?

    The Shining Cow

    Alex James

  • I gave the radar boys the word just before Mantor dropped in on us.

    This One Problem

    M. C. Pease

  • High above the planes they went, for with his radar Arcot could trace them.

    The Black Star Passes

    John W Campbell

  • The Army and the Air Force were furious because he'd evaded their radar net.

    By Proxy

    Gordon Randall Garrett

  • There were guards surrounding the perimeter with radar search beams.

    A Spaceship Named McGuire

    Gordon Randall Garrett

British Dictionary definitions for radar


  1. a method for detecting the position and velocity of a distant object, such as an aircraft A narrow beam of extremely high-frequency radio pulses is transmitted and reflected by the object back to the transmitter, the signal being displayed on a radarscope. The direction of the reflected beam and the time between transmission and reception of a pulse determine the position of the objectFormer name: radiolocation
  2. the equipment used in such detection

Word Origin for radar

C20 ra (dio) d (etecting) a (nd) r (anging)
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 radar

"electronic system for locating objects by means of radio waves," 1941, acronym (more or less) from radio detecting and ranging. The U.S. choice, it won out over British radiolocation. Figurative from 1950.

Online Etymology Dictionary, © 2010 Douglas Harper

radar in Science


  1. A method of detecting distant objects and determining their position, speed, material composition, or other characteristics by causing radio waves to be reflected from them and analyzing the reflected waves. The waves can be converted into images, as for use on weather maps.
  2. The equipment used in such detecting. See also Doppler effect lidar sonar.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

radar in Culture


A method of finding the position and velocity of an object by bouncing a radio wave off it and analyzing the reflected wave. Radar is an acronym for radio detection and ranging.


Police use radar techniques to determine the speed of automobiles.
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.