CONJ-SUBORD
唯恐；免得
If you do something lest something unpleasant should happen, you do it to try to prevent the unpleasant thing from happening.
例句
I was afraid to open the door lest he should follow me...
我不敢開門，唯恐他還跟著我。
The president has gone along with the hardliners lest they be tempted to oust him...
總統同意了強硬派的意見，以免他們產生趕他下臺的念頭。