excitant vs drug

excitant and drug both are nouns.

Word	Noun	Adjective	Verb	Adverb
excitant	Yes	Yes	No	No
drug	Yes	No	Yes	No

As nouns, drug is a hypernym of excitant; that is, drug is a word with a broader meaning than excitant:

excitant (noun)	drug (noun)
a drug that temporarily quickens some vital process	a substance that is used as a medicine or narcotic

excitant (adjective)	drug (adjective)
(of drugs e.g.) able to excite or stimulate

excitant (verb)	drug (verb)
	administer a drug to
	use recreational drugs