backpack vacuum vs vacuum

backpack vacuum and vacuum both are nouns.

Word	Noun	Adjective	Verb	Adverb
backpack vacuum	Yes	No	No	No
vacuum	Yes	No	Yes	No

As nouns, vacuum is a hypernym of backpack vacuum; that is, vacuum is a word with a broader meaning than backpack vacuum:

backpack vacuum: a small canister vacuum strapped onto the user's back, commonly used for commercial cleaning.
vacuum: an electrical home appliance that cleans by suction

Other hypernyms of backpack vacuum include vacuum cleaner.

backpack vacuum (noun)	vacuum (noun)
a small canister vacuum strapped onto the user's back, commonly used for commercial cleaning.	an electrical home appliance that cleans by suction
	a region that is devoid of matter
	an empty area or space
	the absence of matter

backpack vacuum (verb)	vacuum (verb)
	clean with a vacuum cleaner