Marksman is worn out (4)
I believe the answer is:
shot
This clue is a double definition.
'marksman' is the first definition.
(I've seen this in other clues)
'is worn out' is the second definition.
(I've seen this in another clue)
(Other definitions for shot that I've seen before include "Hit by gun" , "description of some silk" , "Attempt (to kill?)" , "injured or killed?" , "glass of spirits" .)