Freezeout
A freezeout is a tournament in which every player starts with the same stack and plays until they lose all their chips. There are no rebuys or re-entries, so once you are out, you are out.
The simple explanation
The freezeout is the standard format for tournaments. Everyone pays the same buy-in and gets the same number of chips. When you lose all your chips, you are eliminated, and the last player left takes the top prize. There is no way to buy more chips.
A closer look
The name comes from the fact that chips are 'frozen' in the game once they are in play: they cannot be replaced by outside money. A freezeout differs from a rebuy tournament, in which players can buy more chips during the first levels, and from a re-entry event, in which a busted player can register again. Strategy in a freezeout tends to be tighter early than in a rebuy tournament, because you have only one stack.
A practical example
A tournament has 100 players, each with 10,000 chips and no rebuys. A player who loses all 10,000 chips is out of the freezeout.
Full explanation
A freezeout is a tournament in which every player starts with the same stack and plays until they lose all their chips. There are no rebuys or re-entries, so once you are out, you are out.
A freezeout is a tournament where you cannot buy more chips. Once you lose all of yours, you are eliminated.
It is the most common tournament format.
In a rebuy or re-entry tournament you may get another chance, but not in a freezeout.
The winner is the last player left with all of the chips.
Alternative spelling: freeze-out, freeze out