World War II weapon (4)
I believe the answer is:
sten
'world war ii weapon' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for sten that I've seen before include "name of gun" , "Light sub-machine (gun)" , "Such as rapidly discharges" , "Type of light WWII machine gun" , "Type of machinegun" .)