A transaction in which one party, the "reinsurer," in consideration of a premium paid to it, agrees to indemnify another party, the "reinsured," for part or all of the liability assumed by the reinsured under a policy of insurance that it has issued. The reinsured may also be referred to as the "original" or "primary" insurer or the "ceding company."
Definition provided by the International Risk Management Institute (IRMI) Glossary of Insurance.