A hostage is a person seized by an abductor in order to compel another party, one which places a high value on the liberty, well-being and safety of the person seized—such as a relative, employer, law enforcement, or government—to act, or refrain from acting, in a certain way, often under threat of serious physical harm or death to the hostage(s) after expiration of an ultimatum. The Encyclopædia Britannica Eleventh Edition defines a hostage as "a person who is handed over by one of two belligerent parties to the other or seized as security for the carrying out of an agreement, or as a preventive measure against certain acts of war."