passiveness vs inactivity

passiveness and inactivity both are nouns.

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

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

Other hypernyms of passiveness include inactiveness, inertia.

passiveness (noun)	inactivity (noun)
the trait of remaining inactive; a lack of initiative	being inactive; being less active
submission to others or to outside influences	a disposition to remain inactive or inert
	the state of being inactive