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

Amazon just dropped under-the-radar deals that are just for Prime members. —Isabel Garcia, PEOPLE, 25 Oct. 2025

Scroll on for the best under-the-radar outdoor finds that can give your deck, patio, or balcony an instant refresh. —Mariana Best, Better Homes & Gardens, 24 Oct. 2025

This created a tunable metasurface, a structured layer that manipulates how waves interact with the surface, allowing the coating to absorb radar signals across various frequencies. —Kapil Kajal, Interesting Engineering, 24 Oct. 2025

African photography’s going to be on the radar in a big way. —Folasade Ologundudu, Vogue, 24 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