In poker, an ante is a forced bet that all players must risk. Upping the ante simply means to raise stakes. The risk is bigger, but so is the reward. Ante means before  in Latin.

Ante. An ante is a forced bet in which all players put an equal amount of money or chips into the pot before the deal begins. Often this is either a single unit (a one-value or the smallest value in play) or some other small amount; a proportion such as a half or a quarter of the minimum bet is also common.