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

The shipborne system draws tracking data from the Baden-Württemberg’s TRS-4D AESA radar, integrated into its combat management system. —Aamir Khollam, Interesting Engineering, 17 Oct. 2025

The remote Aroostook National Wildlife Refuge is another under-the-radar aurora zone free of light pollution. —Lydia Price, Travel + Leisure, 17 Oct. 2025

Simon’s radar went up another notch or two. —Lizz Schumer, PEOPLE, 17 Oct. 2025

While growing up outside of Columbus, Ohio, in the shadow of the Horseshoe, Smith was on Ohio State’s recruiting radar but the Buckeyes went a different direction. —Dane Brugler, New York Times, 16 Oct. 2025

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