United were victorious according to report (3)
I believe the answer is:
'united' is the definition.
(as in a phrase like 'we are one')
'were victorious according to report' is the wordplay.
'were victorious' becomes 'won' (to win is to be victorious).
'according to report' shows a homophone (sound like).
'won' sounds like 'ONE'.
(Other definitions for one that I've seen before include "Sole; identical" , "Lowest cardinal number" , "This is singular" , "Unit" , "Half of two" .)