"The Godfather” group (5)
I believe the answer is:
mafia
'the godfather group' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for mafia that I've seen before include "Group exerting a hidden sinister influence" , "Criminal group" , "Italian criminal organisation" , "Criminal organisation with origin in Sicily" , "Gangsters" .)