imperative vs instant

imperative and instant both are nouns.

Word	Noun	Adjective	Verb	Adverb
imperative	Yes	Yes	No	No
instant	Yes	Yes	No	No

imperative (noun)	instant (noun)
some duty that is essential and urgent	a particular point in time
a verb in the imperative mood.	a very short time (as the time it takes the eye to blink or the heart to beat)
a mood that expresses an intention to influence the listener's behavior

imperative (adjective)	instant (adjective)
requiring attention or action	occurring with no delay
relating to verbs in the imperative mood	demanding attention
	in or of the present month