back-porch money
n.— «That’s not to say street money doesn’t cause problems. For one thing, by the time it reaches ward leaders, it is cash. While some ward leaders are assiduous about keeping receipts and filing the necessary public reports, others aren’t. Indeed, some ward leaders have—surprise!—skimmed money before it reached the street. There is even a name for this, “back-porch money”—not enough to build a house, but enough to get yourself a nice new porch.» —“Cash and Carry (the City)” by Tom Ferrick Jr. in Philadelphia, Pennsylvania New York Times Apr. 22, 2008. (source: Double-Tongued Dictionary)