(1):

(v. t.) To treat as an enemy.

(2):

(n.) One who opposes on principle; an opponent; an adversary; an ill-wisher; as, a foe to religion.

(3):

(n.) One who entertains personal enmity, hatred, grudge, or malice, against another; an enemy.

(4):

(n.) An enemy in war; a hostile army.