Riot (6)
I believe the answer is:
tumult
'riot' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tumult that I've seen before include "A lot of noise, uproar" , "Violent disturbance" , "State of confusion and agitation, uproar" , "Hubbub" , "Clamour" .)