Definition of freeroll
A freeroll has many meanings. A freeroll can be a free entry into a contest or lotto. If you find a lotto ticket on the ground and the draw is coming up, you have a freeroll. Your cost of participation is 0 and you have a potential payout ahead of you. In poker, a freeroll can be a tournament that beginners are entitled to. Some poker rooms will offer beginners free tournaments with 100 Euros in prize money (more or less 100 Euros, depending on the tournament). These are called freeroll tournaments.
A freeroll on an all-in game
A freeroll is also when you have a made hand like your opponent, but you also have a draw. Imagine a 3bet pot in which you have AK in hearts. Your opponent has AK in spades. The flop comes A-2-5 with 2 hearts and you are all in on the flop. In this case you have a freeroll because your losing odds are 0. In the worst case scenario, you will win half the pot and if you hit your draw, you will win the entire prize pool. Having a chance to win a prize with no cost or loss to you is a freeroll.
