Dollar Bet

A dollar bet is a term used to indicate a $100 bet. The reason for the name could probably be traced to the fact that a dollar is composed of 100 cents. As a dollar is usually too small an amount of money to be used in gambling and sports betting, the term dollar started to be used for $100. 

The term dime bet is also sometimes used to indicate a $100 bet.

Dollar bet:

• A bet of $100.