What is a life annunity? What is a 'Life Annuity'. A life annuity is an insurance product that features a predetermined periodic payout amount until the death of the annuitant. They are commonly used to provide for a guaranteed income in retirement that cannot be outlived.What is annuity explanation? By definition, an annuity is a contract between you and a 3rd party (usually an insurance company) whereby in exchange for making a lump sum payment, the insurance company promises to do four things: Provide an income for a certain period of time,or for life. Provide for accumulation, or asset growth.What is an annuity insurance? An annuity is a long-term contract you purchase from an insurance company. It is designed to help accumulate assets to provide income for retirement. ... An annuity is a long term investment that is issued by an insurance company designed to help protect you from the risk of outliving your income.