sonar
/ˈsəʊnɑː(r)/noun
mass noun
1- a system for the detection of objects under water by emitting sound pulses and detecting or measuring their return after being reflected声呐。
1.1
- count noun an apparatus used in this system声波定位仪。
1.2
- the method of echolocation used in air or water by animals such as whales and bats声呐定位法。
词源
1940s: from so（und） na（vigation and） r（anging）， on the pattern of radar.