Uproar in prison (4)
I believe the answer is:
stir
I believe this is a double definition.
'uproar' is the first definition.
(I've seen this in another clue)
'prison' is the second definition.
(informal term for prison)
'in' acts as a link.
(Other definitions for stir that I've seen before include "Wake; disturbance" , "Wake up - prison" , "Agitate; wake from sleep" , "Cause to move in slangy prison" , "Arouse (a memory)" .)