Langimage
English

perfidy

|per/fi/dy|

C2

🇺🇸

/ˈpɝfɪdi/

🇬🇧

/ˈpɜːfɪdi/

betrayal of trust

Etymology
Etymology Information

'perfidy' originates from Latin, specifically the word 'perfidia', where 'per-' meant 'thoroughly/through' and 'fides' meant 'faith'.

Historical Evolution

'perfidy' changed from medieval/Old French and Anglo-Norman forms such as 'perfidie'/'perfide' and entered Middle English as 'perfidy', eventually becoming the modern English word 'perfidy'.

Meaning Changes

Initially, it meant 'breach of faith' or 'faithlessness'; over time it has retained that core sense but is often used more broadly for deceitfulness or treacherous conduct.

Meanings by Part of Speech

Noun 1

breach of trust; deceptive or treacherous behavior toward someone who trusts you.

The diplomat's perfidy undermined the negotiations and caused a loss of trust between the countries.

Synonyms

Antonyms

Noun 2

an act of deliberate betrayal or treacherous conduct (often used of a specific action rather than a general trait).

Selling company secrets to a competitor was an unforgivable perfidy.

Synonyms

betrayalbackstabbingtreachery

Antonyms

Last updated: 2025/12/04 04:00