sonar

American  

[soh-nahr] / ˈsoʊ nɑr /

noun

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

2. the apparatus used in sonar.

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sonar British  

/ ˈsəʊnɑː /

noun

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

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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

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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

"We watched them, we were able to track them, we dropped sonar buoys to demonstrate to them that we were monitoring every hour of their operation."

From BBC • Apr. 9, 2026

The scientists used high resolution sonar to produce a detailed map of the seafloor.

From Science Daily • Feb. 23, 2026

During air strikes, GPS signals are scrambled, making sonar readings imprecise.

From BBC • Jan. 30, 2026

Rescuers continue their search, aided by divers and sonar systems, Fathur said.

From Barron's • Jan. 4, 2026

“I hope that was a joke. This is Camp_____.” He made a sound that was a series of sonar pings and hisses.

From "The Mark of Athena" by Rick Riordan