›to protect yourself against risk by buying insurance from a company that will provide an agreed amount of money if a particular event happens, for example if you are killed or injured or if your possessions are damaged or stolen: insure sb/sth/yourself against sthWe hadn't insured the bicycles against theft. insure sth for sth The antique dealer said we should insure the desk for at least £2,000.
›to provide insurance for someone or something: insure sb/sth against sthWe can insure you against most of the risks involved in owning and operating a boat.