Kick the hired horse (4)
I believe the answer is:
hack
This clue might be a double definition.
'kick' is the first definition.
(I've seen this before)
'hired horse' is the second definition.
'hack' can be an answer for 'horse' (hack is a kind of horse). I am not sure about the 'hired' bit.
'the' is the link.
Can you help me to learn more?
(Other definitions for hack that I've seen before include "Cut roughly; journalist" , "Cut crudely - journalist" , "Chop - reporter" , "Journo" , "Kick on the shins" .)