Fires and tries to kill leader (4)
I believe the answer is:
axes
'fires' is the definition.
(I've seen this before)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for axes that I've seen before include "Edge tools with metal heads" , "Tools with heavy-bladed heads" , "Chopping tools" , "Drastically cuts" , "equipment for lumberjack" .)