1. in a way that betrays one’s country, cause, or trust; disloyally

Examples

• The spy acted traitorously by selling state secrets to enemy agents.
• He was accused of behaving traitorously toward his former allies.
• The general was court-martialed for traitorously abandoning his post.
• She felt he had acted traitorously by revealing her confidential plans.
• The politician was criticized for traitorously switching parties for personal gain.
• The captain was charged with traitorously surrendering the fort without a fight.