black market

Definitions

Economics

  • noun the buying and selling goods or currency in a way which is not allowed by law, as when a government imposes price controls or rationing. The prices on a black market are always higher than regular prices.

Law

Military

  • noun an illicit trade in articles which are illegal, rationed or difficult to obtain, usually at a considerable profit

Travel

  • noun a system for buying and selling goods in a way which is not allowed by law, e.g. in a time of rationing

Idiom of “black market”

system of trading that omits to keep business accounts in accordance with the laws governing a country’s trade
http://www.dictionarycentral.com/definition/black-market.html