slush fund
US /ˈslʌʃ ˌfʌnd/
UK /ˈslʌʃ ˌfʌnd/
1.
a reserve of money used for illicit purposes, especially political bribery
:
•
The politician was accused of using a slush fund to pay off witnesses.
•
Investigators uncovered a massive slush fund used for illegal campaign activities.