Opponent and Traducer

Opponent noun - One that takes a position opposite another in a competition or conflict.

Traducer and opponent are semantically related In some cases you can use "Traducer" instead a noun "Opponent".

Traducer noun - One who attacks the reputation of another by slander or libel.

Opponent and traducer are semantically related in someone hated or competed against topic. Sometimes you can use "Opponent" instead a noun "Traducer".