a person who feels hatred for, fosters harmful designs against, or engages in antagonistic activities against another; an adversary or opponent.

an armed foe; an opposing military force

The army attacked the enemy at dawn.

a hostile nation or state.

a citizen of such a state.

enemies, persons, nations, etc., that are hostile to one another

Let's make up and stop being enemies.

something harmful or prejudical

His unbridled ambition is his worst enemy.

the Enemy, the Devil; Satan.

belonging to a hostile power or to any of its nationals

enemy property.

Obsolete . inimical; ill-disposed.

noun

aide , ally , assistant , confidante , friend , helper

noun

adversary , agent , antagonist , archenemy , asperser , assailant , assassin , attacker , backbiter , bad person , bandit , betrayer , calumniator , competitor , contender , criminal , defamer , defiler , detractor , disputant , emulator , falsifier , fifth column , foe , guerrilla , informer , inquisitor , invader , murderer , opponent , opposition , other side , prosecutor , rebel , revolutionary , rival , saboteur , seditionist , slanderer , spy , terrorist , traducer , traitor , vilifier , villain , nemesis , combatant , hostile , roe