lest

形容词 l:

1. being ten more than forty
   同义词：fifty, 50, l

1. Beware your hat, lest it should be blown away.
   当心你的帽子别被吹走。
2. He took a flashlight lest it should get dark before he returned.
   为了预防回来以前天就黑了，所以他带着手电筒。
3. Hide it lest he (should) see it.
   把它藏起来免得他看见。
4. We talked in a low voice lest we should wake the baby up.
   我们小声说话以免吵醒婴儿。
5. I got up early lest I (should) miss the train.
   我早起以免错过了火车。
6. They spoke in whispers lest they should be heard.
   他们低声说话，唯恐被别人听见。

lest

conj.（连接词）
For fear that:
唯恐，以免：
例句：
tiptoed lest the guard should hear her; anxious lest he become ill.
踮起脚趾走路，以免守卫发现她；唯恐他生病而感到焦虑

来源：
Middle English
中古英语
from Old English tht lôs the [so that not]
源自 古英语 tht lôs the [为了不使]
from lôs [less] * see less
源自 lôs [较少的，更小的] *参见 less