by the skin of your teeth意思是勉强、几乎没有成功或幸免于难。它形象地描述了在困难或危险情况下仅以微小的差距或幸运而成功或脱险。

【例句】
We made it to the airport by the skin of our teeth. The traffic was terrible.
我们勉强赶到机场，交通状况很糟糕。

The team won the game by the skin of their teeth. It was a last-minute goal.
这个团队勉强赢得了比赛。最后一刻进球。