Police often train to recover hostages taken by force, as in this exercise.
A hostage is a person seized by a criminalabductor in order to compel another party 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 to the hostage(s) after expiration of an ultimatum. The 1911 edition of the Encyclopædia Britannica 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."
A person who seizes one or more hostages is known as a hostage-taker; if the hostages are present voluntarily, then the receiver is known as a host.
The English word "hostage" derives from Frenchostage, modern otage, from Late Latinobsidaticum (Medieval Latinostaticum, ostagium), the state of being an obses (plural obsides), "hostage", from Latin obsideō ("I haunt/frequent/blockade/besiege"), but an etymological connection was later supposed with Latinhostis ("stranger," later "enemy").