Nest egg

Savings set aside for future use.

The allusion is to putting a real or china egg into a hen's nest to encourage her to lay. The connection between this and the 'savings' meaning isn't exactly clear. It may be that the idea was that the egg that was put into the nest could be later retrieved, after the hen had laid.



Ex: I have set aside a little money as a nest egg for when we retire.



Spanish: colchón



German: Nestei