Definition of radar in English:

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Pronunciation: /ˈrāˌdär/


1A system for detecting the presence, direction, distance, and speed of aircraft, ships, and other objects, by sending out pulses of high-frequency electromagnetic waves that are reflected off the object back to the source.
Example sentences
  • Chavez reported that Venezuelan radar detected the presence of the ships and planes during the coup attempt.
  • That expelling of exhaust is vital in detecting their presence on radar.
  • Digital cellphones are similar to radar, using pulses carried by microwaves.
1.1An apparatus used for radar.
Example sentences
  • Invading foreign computer networks could shut down radars and electrical plants and disrupt telephone lines without firing a shot.
  • Cyclone detection doppler radars are replacing the conventional analogue radars in important locations along the east coast.
  • Park Air is a world leader in the field of integration, processing and display of data from radars, sensors and databases.
1.2Used to indicate that someone or something has or has not come to the attention of a person or group: the band has been kind of off the radar these past few years
More example sentences
  • From a finance standpoint, Telemundo is the merest blip on GE's radar.
  • His private life better known in Britain than here at home has not appeared on the radar of the Canadian media.
  • Just a couple of things we want to put on your radar, certainly on our radar, this morning.


1940s: from ra(dio) d(etection) a(nd) r(anging).

  • This system for detecting objects by sending out radio waves which are reflected back was developed in the 1930s. The name comes from the opening letters of radio detection and ranging, and was coined in 1941. Police started using radar traps to detect speeding motorists in the early 1960s. In the Second World War the myth that pilots ate lots of carrots to help them see in the dark was spread to explain how they could detect enemy planes, as radar was still a secret. Other words have been coined on the pattern of radar, such as lidar (mid 20th century), which works like radar, but uses light from lasers (mid 20th century)—laser itself being an acronym from ‘light amplification by the stimulated emission of radiation’.

For editors and proofreaders

Syllabification: ra·dar

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