sonar vs measuring device

sonar and measuring device both are nouns.

Word	Noun	Adjective	Verb	Adverb
sonar	Yes	No	No	No
measuring device	Yes	No	No	No

As nouns, measuring device is a hypernym of sonar; that is, measuring device is a word with a broader meaning than sonar:

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
measuring device: instrument that shows the extent or amount or quantity or degree of something

Other hypernyms of sonar include measuring instrument, measuring system, navigational instrument.

sonar (noun)	measuring device (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	instrument that shows the extent or amount or quantity or degree of something