alarm vs fire alarm

alarm and fire alarm both are nouns.

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

As nouns, fire alarm is a hyponym of alarm; that is, fire 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, smoke alarm, horn, siren.

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

Other hyponyms of alarm include torpedo, air alert, burglar alarm, foghorn, fogsignal, horn, red flag, siren, alarm bell, tocsin.

alarm (noun)	fire 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	a shout or bell to warn that fire has broken out
an automatic signal (usually a sound) warning of danger
fear resulting from the awareness of danger

alarm (verb)	fire 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