Synonyms: enemy, foe, foeman, opposition
Definition: an armed adversary (especially a member of an opposing military force)
Usage: a soldier must be prepared to kill his enemies
Similar words: adversary, antagonist, opponent, opposer, resister
Definition: someone who offers opposition
Definition: a personal enemy
Usage: they had been political foes for years
Similar words: rival, contender, challenger, competition, competitor
Definition: the contestant you hope to defeat
Usage: he had respect for his rivals; he wanted to know what the competition was doing