alarm vs burglar alarm

alarm and burglar alarm both are nouns.

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

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

alarm: a device that signals the occurrence of some undesirable event
burglar alarm: a warning device that is tripped off by the occurrence of a burglary

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

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

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

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

alarm (verb)	burglar 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