Monopoly money

Noun

Monopoly money (uncountable)

1. Play money.

   Synonyms:

   toy currency, fun money, play money

2. (derogatory, often, slang) Banknotes of foreign currency; especially those which are vibrant or flimsy.

   Synonyms:

   play money, funny money

3. Money, especially paper money, that is perceived to have little or no value, or to be distributed freely.
4. (idiomatic) Money that does not exist; referring to fraudulent record keeping.
   • 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.2005, Craig M. Boise, Playing with ‘Monopoly Money’: Phony Profits, Fraud Penalties and Equity, Minnesota Law Review, volume 90, page 144