alarm system vs hooter

alarm system and hooter both are nouns.

Word	Noun	Adjective	Verb	Adverb
alarm system	Yes	No	No	No
hooter	Yes	No	No	No

As nouns, hooter is a hyponym of alarm system; that is, hooter is a word with a more specific, narrower meaning than alarm system:

alarm system: a device that signals the occurrence of some undesirable event
hooter: a device on an automobile for making a warning noise

Other hyponyms of alarm system include automobile horn, car horn, horn, motor horn, burglar alarm, fire alarm, smoke alarm, horn, siren.

alarm system (noun)	hooter (noun)
a device that signals the occurrence of some undesirable event	nocturnal bird of prey with hawk-like beak and claws and large head with front-facing eyes
	a device on an automobile for making a warning noise
	informal terms for the nose