Deserter or turncoat (8)
I believe the answer is:
renegade
This clue is a double definition.
'deserter' is the first definition.
(I know that deserter can be written as renegade)
'turncoat' is the second definition.
(I know that turncoat can be written as renegade)
(Other definitions for renegade that I've seen before include "Dare Gene to become a rebel" , "Person who deserts from cause or faith" , "Betrayer, deserter" , "A deserter from a cause or faith" , "One who deserts cause or faith" .)