Quiz: Remember the definition of mal de mer?
late 13c., from Old French hostage "person given as security or hostage" (12c., Modern French ôtage), either from hoste "guest" (see host (n.1)) via notion of "a lodger held by a landlord as security," or from Late Latin obsidanus "condition of being held as security," from obses "hostage," from ob- "before" + base of sedere "to sit" [OED]. Modern political/terrorism sense is from 1970.
a person delivered into the hands of another as a security for the performance of some promise, etc. (2 Kings 14:14; 2 Chr. 25:24).