perfidy.

Deliberate disloyalty or betrayal of a trust.

Use it for

Words that belong together

• act of perfidy
• political perfidy

On the page

The act of perfidy destroyed an alliance older than the city.

She learned of his political perfidy from a letter meant for someone else.

Usage notes

Primary category: psychological / character. Forms: Usually uncountable. Legacy lexical fields mirror sense 1 only. Use numbered sense fields for all meanings.