Source : Webster's Revised Unabridged Dictionary (1913)

Hostage \Hos"tage\, n. [OE. hostage, OF. hostage, ostage, F.
   [^o]tage, LL. hostaticus, ostaticum, for hospitaticum, fr. L.
   hospes guest, host. The first meaning is, the state of a
   guest, hospitality; hence, the state of a hostage (treated as
   a guest); and both these meanings occur in Old French. See
   {Host} a landlord.]
   A person given as a pledge or security for the performance of
   the conditions of a treaty or stipulations of any kind, on
   the performance of which the person is to be released.

         Your hostages I have, so have you mine; And we shall
         talk before we fight.                    --Shak.

         He that hath a wife and children hath given hostages to
         fortune.                                 --Bacon.

Source : WordNet®

hostage
     n : a prisoner who is held by one party to insure that another
         party will meet specified terms [syn: {surety}]