Splitting tool (3)
I believe the answer is:
axe
'splitting tool' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for axe that I've seen before include "Abandon project with chopping tool" , "Fire weapon" , "Terminate - with a hatchet?" , "Cut costs or staff drastically" , "US jazz instrument" .)