1. betrayal of trust; deliberate disloyalty or deception

Examples

• The spy’s treachery was discovered when classified documents went missing.
• She felt betrayed by her friend’s treachery in revealing her secrets.
• The general’s treachery led to the defeat of his own army.
• Political treachery often involves breaking campaign promises.
• The novel explores themes of love, honor, and treachery.
• His treachery shocked everyone who had trusted him.
• The company’s treachery toward its employees became public knowledge.