hooter vs warning device

hooter and warning device both are nouns.

Word	Noun	Adjective	Verb	Adverb
hooter	Yes	No	No	No
warning device	Yes	No	No	No

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

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

Other hypernyms of hooter include alarm, alarm system.

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