- a small sum of money carried or kept in reserve for minor expenses, emergencies, or impulse purchases.
- a small sum of money carried by a woman on a date to enable her to reach home alone in case she and her escort quarrel and separate.
Origin of mad money
First recorded in 1915–20
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018