United supporters going round creating chaos (5)
I believe the answer is:
snafu
'chaos' is the definition.
(I've seen this before)
'united supporters going round' is the wordplay.
'united' becomes 'u'.
'supporters' becomes 'fans' (fan is a kind of supporter).
'going round' says the letters should be written in reverse.
'u'+'fans'='ufans'
'ufans' backwards is 'SNAFU'.
'creating' is the link.
(Other definitions for snafu that I've seen before include "Mess table" , "Customary confusion" , "confused activity" , "Bloomer" , "Slangy acronym meaning in total confusion" .)