perfidy
treachery or breach of faith
Root
- fid: trust or faith
Other words with the fid root
- confidence: trust in oneself or something
- diffidence: lack of self-confidence
- diffident: lacking confidence
- faith: trust or belief kept
- fidelity: faithfulness or loyalty
- perfidious: treacherous or deliberately faithless
Perfidy is trust betrayed. The fid root is still there but the faith has been broken.
The spy's perfidy shocked the allies who had trusted him with every plan.