arrest vs inactivity

arrest and inactivity both are nouns.

Word	Noun	Adjective	Verb	Adverb
arrest	Yes	No	Yes	No
inactivity	Yes	No	No	No

As nouns, inactivity is a hypernym of arrest; that is, inactivity is a word with a broader meaning than arrest:

Other hypernyms of arrest include inaction, inactiveness.

arrest (noun)	inactivity (noun)
the act of apprehending (especially apprehending a criminal)	being inactive; being less active
the state of inactivity following an interruption	a disposition to remain inactive or inert
	the state of being inactive

arrest (verb)	inactivity (verb)
hold back, as of a danger or an enemy; check the expansion or influence of
take into custody
attract and fix
cause to come to an abrupt stop