Convict or detainee (8)
I believe the answer is:
prisoner
I believe this is a double definition.
'convict' is the first definition.
(I've seen this before)
'detainee' is the second definition.
(I know that prisoner is a type of detainee)
(Other definitions for prisoner that I've seen before include "One is incarcerated" , "Incarcerated person" , "Person behind bars" , "The ---, cult 60s TV series" , "'Convict, detainee (8)'" .)