Exploits and tricks to get rid of king (4)
I believe the answer is:
uses
'exploits' is the definition.
(use is a kind of exploit)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for uses that I've seen before include "Purposes; consumes" , "Sues (anag.)" , "Employments" , "Consumes; treats" , "Takes (drugs)" .)