- enemy, foe, foeman, opposition - an armed adversary (especially a member of an opposing military force); "a soldier must be prepared to kill his enemies"
--1 is a kind of adversary, antagonist, opponent, opposer, resister
--1 is a member of enemy
--1 has particulars: besieger - foe, enemy - a personal enemy; "they had been political foes for years"
--2 is a kind of rival, challenger, competitor, competition, contender
Antonyms: ally, friend
--2 has particulars: mortal enemy