turncoat
/ˈtɜrnˌkoʊt/
noun
- A person who switches from one party, side, or set of beliefs to another, often seen as a traitor.
- The politician was called a turncoat after joining the opposing party.
- Fans accused the player of being a turncoat when he signed with a rival team.
- In the spy novel, the agent was a turncoat who sold secrets to the enemy.
Antonyms