| knocker(noun, opponent, enemy, critic, censor) |
| caviler(noun, opponent, enemy, attacker, critic) |
| abuser |
| aristarch(noun, opponent, enemy, attacker, critic) |
| attacker(noun, opposition, agent, villain, rebel) |
| backseat driver(noun, expression, opponent, enemy, attacker) |
| blamer(noun, opponent, enemy, attacker, critic) |
| censor(noun, opponent, enemy, attacker, critic) |
| censurer(noun, opponent, enemy, attacker, critic) |
| complainant(noun, opponent, enemy, attacker, critic) |
| complainer(noun, opponent, enemy, attacker, critic) |
| decrier(noun, opponent, enemy, censor, detractor) |
| denigrator(noun, opponent, enemy, attacker, defamer) |
| disapprover(noun, opponent, enemy, attacker, critic) |
| disputer(noun, opponent, enemy, attacker, critic) |
| doubter(noun, opponent, enemy, attacker, critic) |
| enemy(noun, someone, rival, opponent, competitor) |
| faultfinder(noun, opponent, enemy, attacker, critic) |
| fretter(noun, opponent, enemy, attacker, critic) |
| gossiper |