Enraged about English traitor (8)
I believe the answer is:
renegade
'traitor' is the definition.
(I know that renegade is a type of traitor)
'enraged about english' is the wordplay.
'about' indicates anagramming the letters.
'english' becomes 'E' (abbreviation).
'enraged' is an anagram of 'renegad'.
'renegad'+'e'='RENEGADE'
(Other definitions for renegade that I've seen before include "Rebel, outlaw" , "Treacherous person" , "One who deserts a cause or group" , "Treacherous deserter" , "A deserter from a cause or faith" .)