Gangster known as Scarface (6)
I believe the answer is:
capone
'gangster known as scarface' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for capone that I've seen before include "Notorious criminal" , "Hood" , "Al - , notorious gangster" , "US gangster (St Valentine's Day massacre)" , "Chicago gangster, d. 1947" .)