Prison also includes bandit (7)
I believe the answer is:
brigand
'bandit' is the definition.
(synonyms)
'prison also' is the wordplay.
'prison' becomes 'brig' (I've seen this before).
'also' becomes 'and' (both can mean in addition).
'brig'+'and'='BRIGAND'
'includes' is the link.
(Other definitions for brigand that I've seen before include "Gang member" , "Highway robber" , "Robber in wild places" , "Freebooter" , "Marauder" .)