Musket attachment (7)
I believe the answer is:
bayonet
'musket attachment' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for bayonet that I've seen before include "Lethal Weapon" , "one's attached to one's rifle - that's sort of fitting" , "Type of light bulb fitting" , "Muzzle blade" , "Stabbing weapon" .)