To suffer the loss of something by wrongdoing or non-compliance
He forfeited his last chance of an early release from jail by repeatedly attacking another inmate.
To lose a contest, game, match, or other form of competition by voluntary withdrawal, by failing to attend or participate, or by violation of the rules
Because only nine players were present, the football team was forced to forfeit the game.
To be guilty of a misdeed; to be criminal; to transgress.
To fail to keep an obligation.