A Dead Heat is an outcome to a betting market where 2 or more competitors finish the event at the exact same time, or finish with the exact same scores with nothing left to separate their positions.
In the event of a Dead Heat, stakes for bets on both participants are considered as half lost, with half the stake winning and paid at the odds taken. If there are more than 2 participants involved, then the bet stakes are divided further according to the number of players involved.