inactivity vs delay

inactivity and delay both are nouns.

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

As nouns, delay is a hyponym of inactivity; that is, delay is a word with a more specific, narrower meaning than inactivity:

inactivity: being inactive; being less active
delay: the act of delaying; inactivity resulting in something being put off until a later time

Other hyponyms of inactivity include pause, wait, waiting, ease, relaxation, repose, rest, idleness, idling, loafing, holdup.

inactivity (noun)	delay (noun)
being inactive; being less active	the act of delaying; inactivity resulting in something being put off until a later time
a disposition to remain inactive or inert	time during which some action is awaited
the state of being inactive

inactivity (verb)	delay (verb)
	cause to be slowed down or delayed
	stop or halt
	slow the growth or development of
	act later than planned, scheduled, or required