occupy vs exhaust

occupy is not a noun while exhaust is a noun.

Word	Noun	Adjective	Verb	Adverb
occupy	No	No	Yes	No
exhaust	Yes	No	Yes	No

As verbs, exhaust is a hypernym of occupy; that is, exhaust is a word with a broader meaning than occupy:

Other hypernyms of occupy include consume, deplete, eat, eat up, expend, run through, use, use up, wipe out.

occupy (noun)	exhaust (noun)
	system consisting of the parts of an engine through which burned gases or steam are discharged
	gases ejected from an engine as waste products

occupy (verb)	exhaust (verb)
consume all of one's attention or time	wear out completely
march aggressively into another's territory by military force for the purposes of conquest and occupation	eliminate (a substance)
require (time or space)	use up the whole supply of
keep busy with	use up (resources or materials)
assume, as of positions or roles	deplete
live (in a certain place)
occupy the whole of
be on the mind of