asdic vs sonar

asdic and sonar both are nouns.

Word	Noun	Adjective	Verb	Adverb
asdic	Yes	No	No	No
sonar	Yes	No	No	No

As nouns, asdic and sonar are synonyms defined as:

asdic and sonar: 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

Other synonyms of asdic include echo sounder.

asdic (noun)	sonar (noun)
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	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