Prison revolutionary is aroused (7)
I believe the answer is:
stirred
'is aroused' is the definition.
(synonyms)
'prison revolutionary' is the wordplay.
'prison' becomes 'stir' (informal term for prison).
'revolutionary' becomes 'red' (informal term for communist).
'stir'+'red'='STIRRED'
(Other definitions for stirred that I've seen before include "like Earl Grey sometimes?" , "Agitated with a circular motion" , "Rose from sleep" , "Emotionally moved" , "Emotionally stimulated" .)