mad money

Noun

 * 1)  A sum of money, often relatively small in amount, kept in reserve to use for impulsive, frivolous purposes.
 * 2)  A sum of money kept in reserve or to insulate oneself financially in the event of the sudden breakdown of a relationship in which one is economically dependent.
 * 1)  A sum of money kept in reserve or to insulate oneself financially in the event of the sudden breakdown of a relationship in which one is economically dependent.