arsenical vs drug

arsenical and drug both are nouns.

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

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

Other hypernyms of arsenical include pesticide.

arsenical (noun)	drug (noun)
a pesticide or drug containing arsenic	a substance that is used as a medicine or narcotic

arsenical (adjective)	drug (adjective)
relating to or containing arsenic

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