Violent robber (6)
'violent robber' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for bandit that I've seen before include "Outlaw, robber" , "Crook" , "Marauder" , "Armed brigand" , "Armed outlaw" .)
(Other definitions for mugger that I've seen before include "Street robber" , "Robber who takes by threatening violence" , "Violent robber - crocodile" , "Violent street thief" , "Robber who threatens violence" .)