: illicit economic activity done in violation of official regulations
By tax-avoidance and regulation-evasion, the "black economy" amounts to an unofficial but effective supply-side program. George F. Will, Springfield (Massachusetts) Union-News, 14 Sept. 1989
For instance, it taxed gross business income. Thus, tax bills could exceed net profits. So businesses became part of the black economy. And the government didn't know where to get revenue again. P. J. O'Rourke, Rolling Stone, 14 Nov. 1996
The heroin trade funded Pakistan's thriving black economy. Tariq Ali, The Duel, 2008