sonar

American  

[soh-nahr] / ˈsoʊ nɑr /

noun

sonars plural

1. a method for detecting and locating objects submerged in water by echolocation.

2. the apparatus used in sonar.

---

sonar British  

/ ˈsəʊnɑː /

noun

1. a communication and position-finding device used in underwater navigation and target detection using echolocation

---

sonar Scientific  

/ sō′när′ /

1. Short for sound navigation and ranging. A method of detecting, locating, and determining the speed of objects through the use of reflected sound waves. A sound signal is produced, and the time it takes for the signal to reach an object and for its echo to return is used to calculate the object's distance. The Doppler effect can also be used to determine the object's relative velocity. Electronic sonar systems are used for submarine navigation and for detecting schools of fish. Some mammals, especially bats, use biological sonar to navigate and detect prey in dark conditions, commonly called echolocation.

2. The equipment or physiology used in doing this.

3. See also Doppler effect lidar radar

---

Other Word Forms

Noun Inflected Forms

• sonars
  plural

Etymology

Origin of sonar

1940–45; so(und) na(vigation) r(anging)

Compare meaning

How does sonar compare to similar and commonly confused words? Explore the most common comparisons:

• sonar vs. radar

Explanation

Sonar is a method of finding objects under water using sound waves. If the Titanic had been able to use sonar, it never would have hit that iceberg. There are two kinds of sonar: active sonar, which sends sounds out and listens for their echoes, and passive sonar, which records existing sounds. Both allow boat and submarine pilots, explorers, the military, and scientists to determine how far away underwater objects are and approximately how large they are. Leonardo da Vinci gets the credit for inventing sonar when he inserted a tube in the water and listened for the sound of distant ships in 1490.

Example Sentences

See Examples For:

sonar sonars

The region contains faults, volcanic structures, rifts, scarps, and active subduction and spreading zones, many located at depths that make detailed sonar mapping extremely difficult.

From Science Daily ● Jul. 10, 2026

The next day, a team from Chile, utilizing radar and sonar sound-detection equipment, confirmed the presence of Gil, still alive, in the sub-basement.

From Los Angeles Times ● Jul. 5, 2026

Materials known as relaxor ferroelectrics have played an important role for decades in technologies such as ultrasound imaging, microphones, and sonar.

From Science Daily ● May 4, 2026

They are fitted with advanced sonar, radar and submarine hunting helicopters.

From BBC ● Apr. 23, 2026

It was also in 1967 that side-scan sonar proved indispensable in helping George Bass find what was then the world’s oldest shipwreck off the coast of Uluburun, Turkey.

From "Shipwrecked!" by Martin W. Sandler

Mayer and other scientists argued that emerging technologies, especially multibeam sonars that produce detailed 3D images, offered an unprecedented opportunity to document little known sea floors off the U.S.

From Science Magazine ● Jan. 8, 2024

Using a variety of sonars and two remotely operated vehicles — Deep Discoverer and Serios — researchers aboard the ship are mapping and collecting samples from areas along the Aleutian Trench and Gulf of Alaska.

From Seattle Times ● Aug. 14, 2023

National Marine Fisheries Service that concluded the Navy had "killed at least six whales in an accident involving common ship-based sonars."

From Salon ● Jan. 19, 2023

It would dive to just a few hundred feet above the sea floor and then spend 24 hours pinging with different sonars back and forth across about 10 square nautical miles.

From New York Times ● Nov. 10, 2019

Because of their sonar-blinding systems, Tom realized there was a chance of the ships losing contact with one another—especially if their analyzer sonars developed trouble.

From Tom Swift and the Electronic Hydrolung by Brey, Charles