1. [ noun ] (nautical,acoustics,transportation) a measuring instrument that sends out an acoustic pulse in water and measures distances in terms of the time for the echo of the pulse to return (sonar is SOund NAvigation Ranging; asdic is Anti-Submarine Detection Investigation Committee)
Synonyms: sonar asdic
Related terms: navigational_instrument measuring_instrument submarine pulse_generator pinger
Similar spelling:   echo_sounding