Agitated revolutionary going to prison (7)
I believe the answer is:
stirred
'agitated' is the definition.
(similar in meaning)
'revolutionary going to prison' is the wordplay.
'revolutionary' becomes 'red' (informal term for communist).
'going to' is a charade indicator (letters next to each other).
'prison' becomes 'stir' (informal term for prison).
'red' after 'stir' is 'STIRRED'.
(Other definitions for stirred that I've seen before include "Began to wake" , "Rose from sleep" , "Agitated with a circular motion" , "like Earl Grey sometimes?" , "Emotionally moved" .)