ra·​dar ˈrā-ˌdär How to pronounce radar (audio)
often attributive
: a device or system consisting usually of a synchronized radio transmitter and receiver that emits radio waves and processes their reflections for display and is used especially for detecting and locating objects (such as aircraft) or surface features (as of a planet)
: range of notice
fell off the radar after losing their first three games

Example Sentences

The approaching planes were detected by radar.
Recent Examples on the Web Sort of flying under the radar these days are the Los Angeles Clippers, a team that’s rounding back into elite form. Pat Graham, Hartford Courant, 27 Dec. 2022 TicWatch flies relatively under the radar compared to brand-name smartwatches from Apple and Samsung. John Thompson, Men's Health, 22 Dec. 2022 There are, however, measures in place for jet owners who want to fly under the radar, so to speak. Los Angeles Times, 21 Dec. 2022 Here's a look back at the other stories that caught our attention that might have flown under the radar. Meredith Deliso, ABC News, 21 Dec. 2022 The toughness displayed by the Bengals’ slot receiver on Sunday shouldn’t go under the radar. Andrew Gillis, cleveland, 18 Dec. 2022 Yet deaths are much less likely to go under the radar than cases. Emma O'brien, Fortune, 18 Dec. 2022 Dividend recaps are usually under the radar, as private companies are not required to make the same level of financial disclosure as public companies. Joe Nocera, New York Times, 17 Dec. 2022 Portugal’s urban centers were already saturated with remote workers, but Madeira, less than a two-hour flight from Lisbon, was still under the radar. Susana Ferreira, WIRED, 16 Dec. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'radar.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


radio detecting and ranging

First Known Use

1941, in the meaning defined at sense 1

Time Traveler
The first known use of radar was in 1941

Dictionary Entries Near radar

Cite this Entry

“Radar.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radar. Accessed 8 Feb. 2023.

Kids Definition


ra·​dar ˈrā-ˌdär How to pronounce radar (audio)
: a device that sends out radio waves for detecting and locating an object by the reflection of the radio waves and that may use this reflection to find out the position and speed of the object

More from Merriam-Webster on radar

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!

Words Named After People

  • name tags
  • Namesake of the leotard, Jules Léotard had what profession?
True or False

Test your knowledge - and maybe learn something along the way.

Solve today's spelling word game by finding as many words as you can with using just 7 letters. Longer words score more points.

Can you make 12 words with 7 letters?