sonar

noun

so·​nar ˈsō-ˌnär 

: a method or device for detecting and locating objects especially underwater by means of sound waves sent out to be reflected by the objects

also : a device for detecting the presence of a vessel (such as a submarine) by the sound it emits in water

Examples of sonar in a Sentence

They detected the submarine by using sonar.

Recent Examples on the Web

Using sonar, lidar, cameras, and electromagnetic sensors, the robot can detect mines, track undersea structures, and conduct change-detection analysis on harbors, pipelines, and cable corridors. —Kapil Kajal, Interesting Engineering, 27 Nov. 2025

Searching for closure Long said friends and volunteers are continuing to search along shorelines while professional crews use sonar, boats, and aviation assets to cover open water. —Caroline Foreback, CBS News, 24 Nov. 2025

Once on the island, Pettigrew and the team of 14 researchers plan to take video and still images before using sonar and magnetometers to investigate the object. —Katie Hunt, CNN Money, 28 Oct. 2025

The teen’s body was reportedly recovered from the water the next day after using sonar to search the reservoir. —Abigail Adams, PEOPLE, 17 Oct. 2025

Word History

Etymology

sound navigation ranging

First Known Use

1943, in the meaning defined above

Phrases Containing sonar

• side-scan sonar

Kids Definition

sonar

noun

so·​nar ˈsō-ˌnär 

: a device for detecting the presence and location of submerged objects (as submarines) by sound waves