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

In conjunction with Central Lakes College and Brainerd Walleye Alliance president Adam Mord, Kempe ran a creel survey on three lakes in the Brainerd area to quantify walleye catch rates by anglers using forward-facing sonar. —Mike McFeely, Twin Cities, 24 Apr. 2026

No boat, no GPS, forward-facing sonar or other electronics. —Cory Schmidt, Outdoor Life, 15 Apr. 2026

They can be detected by sonar on underwater drones or lasers mounted on the drones or even on helicopters and then destroyed safely. —Brad Lendon, CNN Money, 13 Apr. 2026

Traditional submarine detection methods like sonar, radar, or magnetic detection, for example, can be, in part, defeated with the right countermeasures. —Christopher McFadden, Interesting Engineering, 4 Apr. 2026

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