Seal/sil/ ,是确定决定的意思。fate是命运。Seal one's fate，决定命运，往往指不好的命运。
例句
We've been bowling strong all season. Yet everything depends on tonight's play off. We'll be up against our toughest challenger. If they beat us, they'll seal our fate. Since only the winning team will advance to the finals, we've got to play our best!
我们整个赛季发挥得都很好，但关键还是要看今天晚上季后赛的表现。我们要对付的是最厉害的对手。如果他们赢了，一切就都完了，因为谁赢谁就能获得决赛的资格，所以我们一定要发挥出最高水平。
(欢迎在文末下方留言seal one's fate打卡，加强记忆)