Move in prison (4)
I believe the answer is:
stir
This clue is a double definition.
'move' is the first definition.
(stir can mean to make a movement)
'prison' is the second definition.
(informal term for prison)
'in' is the link.
(Other definitions for stir that I've seen before include "Produce disorder < , wake up" , "Arouse (a memory)" , "Move around and mix thoroughly" , "Excite emotionally" , "Start to move" .)