verb vs imperative

verb and imperative both are nouns.

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

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

verb: a content word that denotes an action, occurrence, or state of existence
imperative: a verb in the imperative mood.

verb (noun)	imperative (noun)
a content word that denotes an action, occurrence, or state of existence	some duty that is essential and urgent
the word class that serves as the predicate of a sentence	a verb in the imperative mood.
	a mood that expresses an intention to influence the listener's behavior

verb (adjective)	imperative (adjective)
	requiring attention or action
	relating to verbs in the imperative mood