funny money

Từ điển Oxford Advanced Learner 8th

ˌfunny ˈmoney 7 [funny money] BrE NAmE noun uncountable (informal, disapproving)
1. a ↑currency (= the money used in one country) which is not worth much and whose value can change quickly
2. money that has been forged (= is not real) or stolen or that has come from illegal activities