nest是指“巢，窝，安乐窝，温床”等，nest egg指“巢里面的蛋”，本意是指“储蓄金，储备金”。

【例句】
They have a little nest egg tucked away somewhere for a rainy day.
他们有一点藏在某处的应急积蓄。

Don't worry about the job you lost. We have a little nest egg to live on until you find another.
别担心失业后的生活。我们还有一些积蓄能撑到你找到新工作。