Dueling tool (4)
I believe the answer is:
epee
'dueling tool' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for epee that I've seen before include "Foil for riposte" , "Fencing weapon" , "Duelling blade" , "sharp-edged implement" , "Fencing blade" .)