General Opposites:
* Enemy: This is the most direct opposite, representing someone who is hostile or actively against you.
* Foe: Similar to enemy, indicating someone who is actively opposed to you.
* Opponent: This suggests someone who competes against you in a particular area, like a game or debate.
* Adversary: This emphasizes a person who is hostile and challenging.
Specific Opposites:
* Stranger: This is the opposite of a friend in terms of familiarity and closeness.
* Acquaintance: This suggests someone you know casually but not well.
* Rival: This indicates someone who competes with you for the same thing, like a job or a romantic partner.
Figurative Opposites:
* Betrayer: This is a strong opposite, suggesting someone who acts against your trust.
* Traitor: Similar to betrayer, but often with a more political or ideological context.
* Backstabber: This emphasizes someone who acts against you in a deceitful way.
The best opposite word depends on the specific situation and the nuance you want to convey.