English
perfidy
Perfidy comes from Latin perfidia ‘faithlessness, dishonesty, treachery,…’, and goes back to Proto-Indo-European *bʰeydʰ- ‘to command, to persuade, to trust’.
- Proto-Indo-Europeanc. 4500–2500 BCE*bʰeydʰ-‘to command, to persuade, to trust’reconstructed
- Latinc. 75 BCE–200 CEfides‘faith’
- Latin, derivedc. 75 BCE–200 CEperfidus‘faithless, treacherous, false’
- Latin, derivedc. 75 BCE–200 CEperfidia‘faithlessness, dishonesty, treachery, falsehood, perfidy’
- Middle Frenchc. 1400–1600perfidie
- Englishearliest quotation 1921perfidy
attested reconstructed ? uncertain or disputed
Lineage
- Proto-Indo-Europeanc. 4500–2500 BCE*bʰeydʰ-‘to command, to persuade, to trust’reconstructed
- Latinc. 75 BCE–200 CEfides‘faith’
- Latin, derivedc. 75 BCE–200 CEperfidus‘faithless, treacherous, false’
- Latin, derivedc. 75 BCE–200 CEperfidia‘faithlessness, dishonesty, treachery, falsehood, perfidy’
- Middle Frenchc. 1400–1600perfidie
- Englishearliest quotation 1921perfidy
Earliest quotation: 1921, Lassa Oppenheim with Ronald Francis Roxb, International law: a treatise: “Stratagems must be carefully distinguished strategy from perfidy, since…”
Linked words
through Proto-Indo-European *bʰeydʰ- ‘to command, to persuade, to trust’
federal, confidence, federation, confident, confederate, defy, abide, defiance, affidavit, bode, infidelity, fiduciary, foi, confidant, confide, bide, diffident, 25 more
through Latin fides ‘faith’
Today it means
noun A state or act of violating faith or allegiance; violation of a promise or vow, or of trust.
Language periods are conventional ranges, not dates for this word.
Etymograph / Proto-Indo-European *bʰeydʰ- / perfidy