Synonyms of perfidy

perfidy

noun

ˈpər-fə-dē 

1

as in infidelity

lack of faithfulness especially to one's husband or wife

his wife's perfidy was a moment of uncharacteristic weakness

Synonyms & Similar Words

• infidelity
• adultery
• betrayal
• disloyalty
• treachery
• faithlessness
• perfidiousness
• unfaithfulness
• inconstancy
• falseness
• falsity
• duplicity
• treason
• deception
• lying
• deceit
• double-dealing
• sellout
• double cross

Antonyms & Near Antonyms

• loyalty
• devotion
• faith
• fidelity
• allegiance
• faithfulness
• fealty
• constancy
• steadfastness
• reliability
• devotedness
• dependability
• staunchness
• honesty
• trustworthiness

2

as in treachery

the act or fact of violating the trust or confidence of another

the full cost—both in compromised intelligence and in human life—of the double agent's perfidy is not yet known

Synonyms & Similar Words

• treachery
• betrayal
• treason
• deception
• infidelity
• disloyalty
• faithlessness
• backstabbing
• falseness
• deceit
• unfaithfulness
• abandonment
• lying
• sellout
• falsity
• double cross
• duplicity
• business
• two-timing
• desertion
• double-dealing
• fraud
• guile
• trickery
• informing
• two-facedness
• snitching
• talebearing

Antonyms & Near Antonyms

• loyalty
• fidelity
• allegiance
• devotion
• faithfulness
• steadfastness
• fealty
• reliability
• trustworthiness
• staunchness
• dependability
• defense
• protection
• shield
• safeguard

Example Sentences

Recent Examples of perfidy

More recently, an al Qaeda operative and suspected mastermind behind the 2000 USS Cole bombing — in which suicide bombers sidled up alongside a US warship, waved to the sailors and then detonated explosives — was charged with perfidy, among other crimes. — Harmeet Kaur, CNN Money, 21 Jan. 2026

The report has raised concerns of perfidy, an act of deception by military forces. — Jenna Prestininzi, Freep.com, 13 Jan. 2026

Ever since, the president and his closest allies haven’t stopped trying to repackage the perfidy as patriotism. — Bloomberg Opinion, Twin Cities, 27 Nov. 2025

The ignorance, the hubris, the lies, the perfidy. — Wesley Stenzel, Entertainment Weekly, 31 Oct. 2025