Captive, prisoner (8)
I believe the answer is:
detainee
I believe this is a double definition.
'captive' is the first definition.
(I know that captive is a type of captive)
'prisoner' is the second definition.
(I know that detainee is a type of prisoner)
(Other definitions for detainee that I've seen before include "Someone held in custody" , "confined person" , "Person kept in custody" , "One penned" , "One is held under guard, for political reasons perhaps" .)