Chaotic brawl (5)
I believe the answer is:
melee
'chaotic brawl' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for melee that I've seen before include "Confused crowd" , "Confused conflict, affray" , "Noisy riotous fight" , "Confused fight or scuffle" , "Affray; muddled group" .)