black economy

Definitions

Economics

  • noun the part of an economy involving goods and services which are paid for in cash, and therefore not declared for tax.

Law

  • noun the system by which work is paid for in cash or goods and not declared to the tax authorities

Idiom of “black economy”

that informal – and illegal – part of a country’s economy where money is earned but where no taxes are paid
http://www.dictionarycentral.com/definition/black-economy.html