A stick that can be thrown (6)
I believe the answer is:
switch
'a stick' is the definition.
(thesaurus)
I don't understand the rest of the clue.
Can you help me to learn more?
(Other definitions for switch that I've seen before include "Circuit-breaker" , "Change course" , "Change or cane" , "Electrical control - change sides" , "Change; hair-piece" .)