radar

noun

ra·​dar ˈrā-ˌdär 

often attributive

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

Those are the findings of an exhaustive new survey published in Nature Cities, in which researchers used satellite radar to track 465 urban areas of more than a million people from 2014 to 2023. — Sanidhya Sharma, Scientific American, 30 Oct. 2026

While there's not enough research to know exactly how common avian cholera is, the disease has been on the radar of scientists for decades. — Gabrielle Emanuel, NPR, 29 Oct. 2026

My colleague Lauren Arzbaecher, Shop AD shopping producer, put Quince’s version on my radar last year after talking about it so enthusiastically at the office. — Nashia Baker, Architectural Digest, 29 Oct. 2026

And yet, beneath the radar, music-making devices have proliferated. — Joshua Rothman, New Yorker, 29 Oct. 2026

Word History

Etymology

radio detecting and ranging

First Known Use

1941, in the meaning defined at sense 1

Phrases Containing radar

• anti-radar
• Doppler radar
• fall off the radar
• on someone's radar (screen)
• radar astronomy
• radar beacon
• radar cruise control
• radar detector
• radar gun
• under the radar

Rhymes for radar

• adar
• afar
• ajar
• alar
• alvar
• bazaar
• bizarre
• boxcar
• boyar
• bulbar
• cachar
• cigar

Kids Definition

radar

noun

ra·​dar ˈrā-ˌdär 

: 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

Etymology

from radio detecting and ranging