A roll of banknotes having an outer note of much higher value than those enclosed, thereby creating a deceptive impression of wealth; also in extended use.
Origin
1920s; earliest use found in Variety.
Definition of Michigan bankroll in US English:
Michigan bankroll
(also Michigan roll)
noun
A roll of banknotes having an outer note of much higher value than those enclosed, thereby creating a deceptive impression of wealth; also in extended use.