burglar alarm vs alarm

burglar alarm and alarm both are nouns.

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

As nouns, alarm is a hypernym of burglar alarm; that is, alarm is a word with a broader meaning than burglar alarm:

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

Other hypernyms of burglar alarm include alarm system, warning device.

As nouns, alarm is a hypernym of burglar alarm; that is, alarm is a word with a broader meaning than burglar alarm:

Other hypernyms of burglar alarm include alarum, alert, warning signal.

burglar alarm (noun)	alarm (noun)
a warning device that is tripped off by the occurrence of a burglary	a device that signals the occurrence of some undesirable event
a loud warning signal produced by a burglar alarm	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

burglar alarm (verb)	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