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

There are no craters or evidence of bombs hitting in the surrounding neighborhood, suggesting a great degree of accuracy, said Corey Scher, a researcher who uses satellite imagery and radar data to study landscape changes in armed conflict zones. —Julia Frankel, Los Angeles Times, 6 Mar. 2026

By comparison, a tornado warning is an alert issued when a tornado is seen by on-the-ground spotters or observed in data from weather radars. —Dale Denwalt, Oklahoman, 6 Mar. 2026

Beneath the sea, visibility is low and the radio waves used for radar don’t travel far. —James Dwyer, Fortune, 6 Mar. 2026

Whatever that means in free agency after the season is not on his radar. —Jeff Sanders, San Diego Union-Tribune, 6 Mar. 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
• ansar
• 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