Insurance definition under tax law clarifies maturity-based life policies qualify for deductions when survival conditions are met. The definition of Insurance includes life policies that secure payment of a specified sum on a stipulated maturity date if the insured is alive then, including policies that only return premiums (with or without interest) if death occurs before maturity. It also includes policies effected for a minor so the minor may adopt the policy on attaining majority and secure life insurance, where payment is contingent on the minor being alive on a specified post-adoption date.