Antagonist (5)
'antagonist' is the definition.
(I know that enemy is a type of antagonist)
This is all the clue.
(Other definitions for enemy that I've seen before include "Antagonist" , "other side (like 16)" , "Opposing force" , "Armed adversary" , "Yemen (anag.)" .)
'antagonist' is the definition.
(I know that foe is a type of antagonist)
This is the entire clue.
(Other definitions for foe that I've seen before include "Someone opposing" , "opposing side" , "friend never!" , "Am archaic enemy" , "Evil rival" .)