Gangster's piece (3)
I believe the answer is:
gat
'gangster's piece' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for gat that I've seen before include "Slang for a gangster's pistol" , "Gangster's gun" , "weapon" , "in Indian music, the last bit of raga" , "Revolver (informal)" .)