The term 'nest egg, perhaps' can refer to two different crossword solutions: 'CACHE' and 'IRA'. A CACHE is a collection of items that are hidden or stored away for future use. It is often used to refer to money that is saved for a rainy day. An IRA, or Individual Retirement Account, is a type of savings account that allows individuals to save money for retirement. Contributions to an IRA are tax-deductible and the money in the account grows tax-free until it is withdrawn. Both of these solutions can be used as a nest egg, or a reserve of money that can be used in the future.