antagonist an-TAG-uh-nist noun WS #4

a person or force that opposes or is hostile to someone or something; in literature, the character who opposes the protagonist; in anatomy, a muscle that acts in opposition to another

1. In the chess tournament, her main antagonist was a seasoned player with years of experience.
2. In 'Snow White,' the antagonist is the jealous queen.
3. He saw the new manager as his antagonist in the workplace.
4. When bending the elbow, the triceps are the antagonist to the biceps.
5. The antagonist in the novel was a cunning and ruthless villain.