foe
An enemy.
Example:
Guard: "Ho there! Be ye friend or foe?"
Adventurer: "Uh.....Foe."
Guard: "Then begone with thee! I'll not let ye in!"
Adventurer: "No, wait...!"
Guard: "Ho there! Be ye friend or foe?"
Adventurer: "I was just....Friend."
Guard: "I don't know if ye are telling the truth, but I'll let ye in anyway."
Adventurer: "Thanks....moron."
Guard: "Ho there! Be ye friend or foe?"
Adventurer: "Uh.....Foe."
Guard: "Then begone with thee! I'll not let ye in!"
Adventurer: "No, wait...!"
Guard: "Ho there! Be ye friend or foe?"
Adventurer: "I was just....Friend."
Guard: "I don't know if ye are telling the truth, but I'll let ye in anyway."
Adventurer: "Thanks....moron."