Start to wake (4)
I believe the answer is:
stir
'start to wake' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for stir that I've seen before include "Start to move" , "Sensation" , "Commotion; wake" , "Cause to move in slangy prison" , "Prison (slang) - disturbance" .)