nest egg 储蓄金、筹备的积蓄

Nest egg: Money that has been saved up over a period of time 储蓄金、筹备的积蓄

例：

Over the years Leo has been very disciplined and saved every month. He now has a big nest egg on which he can retire.

利奥这些年来一直很自律，每个月都存钱。现在他有很大一笔积蓄，都可以退休了。