Bolshie (12)
I believe the answer is:
obstreperous
'bolshie' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for obstreperous that I've seen before include "Disruptive" , "Noisily aggressive" , "Sober posture (anag) - unruly" , "Noisily defiant" , "Noisy, hard to control" .)