Drunken bully is very stressing (4-8)
I believe the answer is:
high-pressure
'very stressing' is the definition.
(high-pressure can mean demanding or stressful)
'drunken bully' is the wordplay.
'drunken' becomes 'high' (high can informally mean drunk).
'bully' becomes 'pressure' (bully can mean to pressure or coerce).
'high'+'pressure'='HIGH-PRESSURE'
'is' acts as a link.
(Other definitions for high-pressure that I've seen before include "(Of selling) aggressively persistent" , "Aggressive (selling)" , "Stressful; persuasive" , "Aggressive, forceful" .)