"sonars" in the noun sense
1. sonar, echo sounder, asdic
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 an acronym for sound navigation ranging"
"asdic is an acronym for antisubmarine detection investigation committee"
Source: WordNet® (An amazing lexical database of English)
Princeton University "About WordNet®."
WordNet®. Princeton University. 2010.
View WordNet® License