noun, often attributive
ra·​dar | \ˈrā-ˌdär \

Definition of radar 

1 : 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)

2 : range of notice fell off the radar after losing their first three games

Examples of radar in a Sentence

The approaching planes were detected by radar.

Recent Examples on the Web

The groups say Mississippi, where blacks make up 37 percent of the population, is next on its radar. Deborah Barfield Berry, USA TODAY, "Black women's groups step up efforts to energize African American voters in the South," 9 July 2018 Skedaddle first crossed my radar in January 2017 when the startup was set to transport more than 11,000 people to and from the Women’s March on Washington. Polina Marinova, Fortune, "Term Sheet -- Friday, July 6," 6 July 2018 Our radar is detecting the smoke from the Fort Worth show. Nichole Manna, star-telegram, "Fort Worth's fireworks show was so large it showed up on National Weather Service radar," 5 July 2018 Pokey Chatman and the Indiana Fever weren’t on her radar. Jordan Guskey, Indianapolis Star, "Indiana Fever's Cappie Pondexter: 'I have a lot left in my tank'," 2 July 2018 How did this come across your radar and convince you to work on a bill? NBC News, "This congressman wants to 'abolish ICE.' We asked him how it would work.," 30 June 2018 However, Heize, a singer from South Korea, recently put a bleach-free alternative back on my radar. Devon Abelman, Allure, "K-Pop Star Heize Shows Off Bleach-Free Alternative to Holographic Highlights," 26 June 2018 Below is just a smattering of series to keep on your radar. Trevor Fraser, OrlandoSentinel.com, "Wanna catch a flick?," 19 June 2018 Nine-Nine won two Golden Globes in its first season and landed on my radar. Sauleha Kamal, The Atlantic, "The Character Who Made Me Love Brooklyn Nine-Nine," 12 June 2018

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.

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First Known Use of radar

1941, in the meaning defined at sense 1

History and Etymology for radar

radio detecting and ranging

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Statistics for radar

Last Updated

10 Nov 2018

Look-up Popularity

Time Traveler for radar

The first known use of radar was in 1941

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More Definitions for radar



English Language Learners Definition of radar

: a device that sends out radio waves for finding out the position and speed of a moving object (such as an airplane)


ra·​dar | \ˈrā-ˌdär \

Kids Definition of radar

: a radio device for detecting the position of things in the distance and the direction of moving objects (as distant airplanes or ships)

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Comments on radar

What made you want to look up radar? Please tell us where you read or heard it (including the quote, if possible).


something that serves to warn or remind

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