minus pool
A mutuel pool caused when a horse is so heavily played that, after deductions of state tax and commission, there is not enough money left to pay the legally prescribed minimum on each winning bet. The betting site where the wager was placed is responsible for making up the difference.
MINUS POOL
In pari-mutuel wagering, when after the take is extracted, there is not enough money left to pay winning patrons the minimum bet. The track must then make up the difference.