means A person held captive by someone who threatens them to force a third party into doing, paying, or promising something.

from From Old French 'ostage,' meaning lodging or the keeping of someone, which entered English in the 13th century. It traces back to Latin 'hospes' (guest/host) — the same root behind 'hostel' and 'hospitality' — through the idea of one held in another's keeping. There's also been confusion with Latin 'obses' (a hostage given as a pledge), which may have nudged the meaning; but the lodging-and-keeping line is the well-attested one, leaving 'hostage' as an uneasy cousin of the words for welcoming a guest.