Bitter foe (7)
I believe the answer is:
nemesis
(Other definitions for nemesis that I've seen before include "Greek god of vengeance" , "Bane" , "rival who can't be beaten" , "Avenging deity" , "Unbeatable rival" .)
I believe the answer is:
nemesis
(Other definitions for nemesis that I've seen before include "Greek god of vengeance" , "Bane" , "rival who can't be beaten" , "Avenging deity" , "Unbeatable rival" .)