Noun

1. Play money printed on paper, especially differently colored denominations of the board game Monopoly.
2. Bills of foreign currency which are brightly colored or printed on flimsy paper.
3. Money that doesn't really exist, referring to fraudulent record keeping.
   • 2005, Craig M. Boise, Playing with ‘Monopoly Money’: Phony Profits, Fraud Penalties and Equity, Minnesota Law Review, volume 90, page 144

     They did so to conceal the fact that they were playing with Monopoly money—fabricating profits as phony as the pastel-colored money used in the classic Parker Brothers board game.