black-market vs contraband

black-market is not a noun while contraband is a noun.

Word	Noun	Adjective	Verb	Adverb
black-market	No	Yes	No	No
contraband	Yes	Yes	No	No

As adjectives, black-market and contraband are synonyms defined as:

Other synonyms of black-market include black, bootleg, smuggled.

black-market (noun)	contraband (noun)
	goods whose importation or exportation or possession is prohibited by law

black-market (adjective)	contraband (adjective)
distributed or sold illicitly	distributed or sold illicitly