短语 to fly the nest 的意思是一个人离开父母开始自己独立的生活。

例句

When David started university he had to fly the nest and live alone.

All the children have flown the nest so Mum now has a lot of spare time.

请注意

A nest egg 的意思是存款、储备金。

Jane is going to use her nest egg to buy a big house by the sea.