noun
ill-gotten money; bad coin
Refers to money obtained through dishonest or immoral means, or to counterfeit/debased coinage. Often used in the proverb 悪銭身に付かず (ill-gotten gains are soon lost).
悪銭身に付かずというから、不正なお金はすぐに消えてしまう。
As the saying goes, ill-gotten gains are soon lost, so dishonest money disappears quickly.
彼は悪銭で豪遊していたが、結局はすべて失った。
He lived it up with ill-gotten money, but in the end he lost it all.