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

Cassini radar observations even found northern lakes more than 100 meters deep, filled largely with liquid methane. — Kaif Shaikh, Interesting Engineering, 11 Aug. 2026

Transportation Secretary Sean Duffy and FAA Administrator Bryan Bedford were at the airport Tuesday morning for the installation of a new surface movement radar (SMR). — Tim McNicholas, CBS News, 11 Aug. 2026

There is even a brief potential window for a few tiny raindrops in the Sacramento area Wednesday, although any rain on the radar is unlikely to reach the ground. — Sean MacAday, Sacbee.com, 10 Aug. 2026

The new provision is on Huntersville leaders’ radar too, town spokesman Ethan Smith said, noting that if the provision isn’t changed, the town will have to adjust its sales tax revenue projections in its next budget cycle. — Mary Ramsey, Charlotte Observer, 10 Aug. 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