black market

(noun) people who engage in illicit trade. Synonyms: black market.

(noun) an illegal market in which goods or currencies are bought and sold in violation of rationing or controls. Synonyms: black market.

(verb) deal in illegally, such as arms or liquor. Synonyms: run, black market.

(adj) distributed or sold illicitly. Synonyms: bootleg, black, black-market, contraband, smuggled. Example: "The black economy pays no taxes."