Cover for a gangster (4)
I believe the answer is:
hood
I believe this is a double definition.
'cover' is the first definition.
(I know this)
'gangster' is the second definition.
(I've seen this before)
'for a' is the link.
(Other definitions for hood that I've seen before include "Part of subfusc" , "See 13" , "Thomas -, Eng. poet" , "Outlaw and gangster" , "Cover < the upper part < of tough" .)