あぶく銭ぜに

noun

easy money; ill-gotten gains

Refers to money obtained with little effort, often through luck or dishonest means. Carries a slightly negative or dismissive nuance.

• ギャンブルで儲もうけた金かねはあぶく銭ぜにだから、すぐに使つかってしまった。

  The money I won gambling was easy money, so I spent it right away.

• あぶく銭ぜには身みに付つかないと言いう。

  They say easy money doesn't stick with you.