Outlaw with good report (4)
I believe the answer is:
bang
'report' is the definition.
(report can mean a loud noise)
'outlaw with good' is the wordplay.
'outlaw' becomes 'ban' (banning is a kind of outlawing).
'with' is a charade indicator (letters next to each other).
'good' becomes 'g' (abbreviation).
'ban'+'g'='BANG'
(Other definitions for bang that I've seen before include "Vigorous blow" , "Gun sound" , "Loud noise; fringe" , "Strike violently" , "Sudden noise; fringe" .)