alarm vs smoke alarm

alarm and smoke alarm both are nouns.

Word	Noun	Adjective	Verb	Adverb
alarm	Yes	No	Yes	No
smoke alarm	Yes	No	No	No

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

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

alarm (noun)	smoke alarm (noun)
a device that signals the occurrence of some undesirable event	an alarm that is tripped off by fire or smoke
a clock that wakes a sleeper at some preset time
an automatic signal (usually a sound) warning of danger
fear resulting from the awareness of danger

alarm (verb)	smoke alarm (verb)
warn or arouse to a sense of danger or call to a state of preparedness
fill with apprehension or alarm; cause to be unpleasantly surprised