autoalarm vs receiving system

autoalarm and receiving system both are nouns.

Word	Noun	Adjective	Verb	Adverb
autoalarm	Yes	No	No	No
receiving system	Yes	No	No	No

As nouns, receiving system is a hypernym of autoalarm; that is, receiving system is a word with a broader meaning than autoalarm:

autoalarm: a radio receiving device used on ships that rings an alarm bell when a distress signal is received.
receiving system: set that receives radio or tv signals

Other hypernyms of autoalarm include receiver.

autoalarm (noun)	receiving system (noun)
a radio receiving device used on ships that rings an alarm bell when a distress signal is received.	set that receives radio or tv signals