noun, often attributive
ra·​dar | \ ˈrā-ˌdär How to pronounce radar (audio) \

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 Following Vikander and Fassbender's under-the-radar wedding, the pair honeymooned in Italy. Kara Warner, PEOPLE.com, 8 Sep. 2021 The younger and more under-the-radar Groundswell Society encourages surfers to share the joy of surfing with their peers, regardless of skill level. Jules Struck, The Christian Science Monitor, 3 Sep. 2021 And the pandemic desire for privacy and space has made travelers more aware of these under-the-radar options. Washington Post, 1 Sep. 2021 Some under-the-radar tech news caught my attention last week. Pete Wilkins, Forbes, 31 Aug. 2021 While definitely no longer under-the-radar, there are enough wineries and enough routes to keep the intimate vibes going. Stacey Lastoe, Travel + Leisure, 31 Aug. 2021 Spiller may be the most under-the-radar productive power conference back in the country. Chuck Carlton, Dallas News, 27 Aug. 2021 Here are five under-the-radar ex-factors for Kentucky this season who fall somewhere between stars like Chris Rodriguez and hyped freshmen like Trevin Wallace. Jon Hale, The Courier-Journal, 26 Aug. 2021 Linebacker Gerald Hernandez, a second-team All-County pick last year, has the potential to be an under-the-radar star this season. Adam Lichtenstein, sun-sentinel.com, 25 Aug. 2021

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.

See More

First Known Use of radar

1941, in the meaning defined at sense 1

History and Etymology for radar

radio detecting and ranging

Keep scrolling for more

Learn More About radar

Dictionary Entries Near radar



radar astronomy

See More Nearby Entries 

Statistics for radar

Last Updated

11 Sep 2021

Cite this Entry

“Radar.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/radar. Accessed 20 Sep. 2021.

Style: MLA
MLACheck Mark Icon ChicagoCheck Mark Icon APACheck Mark Icon Merriam-WebsterCheck Mark Icon

Keep scrolling for more

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 How to pronounce radar (audio) \

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)

More from Merriam-Webster on radar

Nglish: Translation of radar for Spanish Speakers

Britannica English: Translation of radar for Arabic Speakers

Britannica.com: Encyclopedia article about radar


Test Your Vocabulary

Difficult Spelling Words Quiz

  • alphabet pasta spelling help
  • Which is the correct spelling?
How Strong Is Your Vocabulary?

Test your vocabulary with our 10-question quiz!

 AlphaBear 2

Spell words. Make bears.

Love words? Need even more definitions?

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