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 first search in November 2013 used ground-penetrating radar, which detected anomalies in the ground and could have indicated the presence of objects in the soil. —Makena Gera, PEOPLE, 4 Jan. 2026

The spacecraft will study Earth using synthetic aperture radar, gathering data at all times of day and in all weather conditions from an altitude of 385 miles (620 kilometers). —Mike Wall, Space.com, 3 Jan. 2026

Acting wasn’t ever really on his radar, with his mom a pediatric nurse and his dad a data analytics manager. —Tess Kenny, Chicago Tribune, 3 Jan. 2026

Cam Schlittler opened up the 2025 season with a strong spring training that put him firmly on the radar of the MLB club — destined to make an impact in the upcoming season. —James O'Connell, New York Daily News, 2 Jan. 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