Captive (7)
'captive' is the definition.
(hostage is a kind of captive)
This is all the clue.
(Other definitions for hostage that I've seen before include "Prisoner - pawn" , "Prisoner held as surety" , "One held as security" , "Prisoner held as security" , "One held for ransom" .)
'captive' is the definition.
(synonyms)
This is the entire clue.
(Other definitions for prisoner that I've seen before include "Rep irons out the captive" , "Person doing porridge?" , "Senior PR (anag) - one in detention" , "One inside" , "Hostage" .)