A hostage is a person or entity which is hel by a captor. The original definition meant that this was 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. However, in modern days, it means someone who is seized by a criminal abductor in order to compel another party such as a relative, employer or government to act, or refrain from acting, in a particular way, often under threat of serious physical harm to the hostage(s) after expiration of an ultimatum.