Definition of sonar in English:

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Pronunciation: /ˈsəʊnɑː/


[mass noun]
1A system for the detection of objects under water by emitting sound pulses and detecting or measuring their return after being reflected: [as modifier]: a weak sonar signal
More example sentences
  • Out in the Atlantic, vast Japanese factory ships work nonstop, using modern sonar detection to spot the tuna shoals they sweep the ocean clean of fish.
  • For instance, he said, its active and passive sonar systems are aging, thus shortening the range of its monitoring.
  • Now, video footage and sonar data proves conclusively that the wreck is not Centaur.
1.1 [count noun] An apparatus used in sonar: we reduced the sensitivity of our scanning sonars
More example sentences
  • It is equipped with a ham radio set, personal computer, global positioning system, two sonars, autopilot and wind wane which steers the boat depending on the direction of the wind.
  • It just seemed to me that it would be more interesting to have things like submarine sonars and old grandfather clocks and lines from famous movies and bird songs and things like that.
  • Acms receives data from the sonars and other sensors and, through advanced algorithms and data handling, displays real time images on the command consoles.
1.2The method of echolocation used in air or water by animals such as whales and bats: the fishing nets are detectable by dolphin sonar
More example sentences
  • Hearing the unusual ping, the animals might turn on their echolocators - their sonar - and then they can sense the net.
  • While the animals lack sonar, they do posses superb directional underwater hearing and the ability to see in near-darkness.
  • They believe that by being in the water with the animals and feeling their sonar they too are receiving a ‘healing’.


1940s: from so(und) na(vigation and) r(anging), on the pattern of radar.

  • sound from Old English:

    There are four different ‘sounds’ in English. The one relating to noise is from Latin sonus. Related words are dissonance (Late Middle English) ‘inharmonious’; resonance (Late Middle English) ‘echo, resound’; resonant (late 16th century); resound (Late Middle English); and sonorous (early 17th century). Sonar, however, is an acronym formed from Sound Navigation and Ranging on the pattern of radar. Sound, meaning ‘in good condition, not damaged or diseased’, is from Old English gesund. In Middle English the prominent sense was ‘uninjured, unwounded’. Use of sound to mean ‘having well-grounded opinions’ dates from the early 16th century; the phrase as sound as a bell appeared in the late 16th century. This puns on the first meaning of sound, and also on the fact that a cracked bell will not ring true. The third sound (Late Middle English) ‘ascertain the depth of water’ is from Old French sonder, based on Latin sub- ‘below’ and unda ‘wave’. The final one for a narrow stretch of water is Middle English from Old Norse sund ‘swimming, strait’, related to swim.

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