Thrashes noisy mobs (5)
I believe the answer is:
routs
I believe this is a double definition.
'thrashes' is the first definition.
(both can mean to defeat heavily)
'noisy mobs' is the second definition.
(rout can mean a riotous crowd)
(Other definitions for routs that I've seen before include "Thoroughly defeats" , "Decisively defeats" , "drubbings" , "Trounces" , "old parties" .)