（確定不移的形勢） foregone conclusion; inevitable outcome
The outcome of this football game is a foregone conclusion.
這場足球賽， 誰勝誰負已成定局。
The die is cast.
已成定局， 無可挽回。
（做最后決定） settle finally; make a final decision
The matter hasn't come to a decision yet.
事情還沒定局。