The act, business, or system of insuring. The state of being insured. A means of being insured. Coverage by a contract binding a party to indemnify another against specified loss in return for premiums paid. The sum or rate for which such a contract insures something. The periodic premium paid for this coverage. A protective measure: biking helmets that provide insurance against a head injury. Sports Of, relating to, or being a score that increases a team's lead enough to prevent the opposing team from tying the game with one more score: an insurance run.