insurer

One that insures, especially an insurance underwriter.

One who or that which insures or makes sure or certain.

One who contracts, in consideration of a stipulated payment called a premium, to indemnify a person or company against certain perils or losses, or against a particular event; an underwriter.

One who, or that which, insures; the person or company that contracts to indemnify losses for a premium; an underwriter.

One who insures.

a financial institution that sells insurance