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
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Antonyms & Near Antonyms
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
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Antonyms & Near Antonyms
Example Sentences
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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
See All Example Sentences for perfidy
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
See All Example Sentences for perfidy
Recent Examples of Synonyms for perfidy
Noun
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Following the news breaking, rumors of infidelity on both sides began circulating on social media.
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The Apartment is a daring dissection of toxicity in the story of an insurance clerk (Jack Lemmon) who lets his co-workers use his apartment to support their infidelity.
Noun
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Peacock’s adventures in treachery The Traitors was the top dog, scoring five prizes including Best Competition Series and Best Host for Alan Cumming.
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Upon learning of Ava’s treachery, Deborah HOWLS.
Noun
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The filings alleged adultery as the reason behind the divorce.
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Public opinion is against adultery.
Noun
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Figo famously made the ultimate betrayal in 2000 when Perez became Real Madrid president for the first time.
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His jealousy provokes an act of betrayal and cruelty.
Noun
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Treating rumors as diagnostic signals of uncertainty or weak trust, rather than disloyalty, helps leaders improve communication and align words with observable actions.
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Easley also argued constructive criticism was too often viewed as disloyalty and that many employees felt safer remaining silent than challenging decisions.
Noun
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For example, French Marshal Henri Petain was showered with ticker tape in 1931 and later convicted of treason for heading the Vichy government that collaborated with the Nazis during World War II.
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War complicates the domestic front, turning any dissent into treason.
Cite this Entry
“Perfidy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/perfidy. Accessed 26 Jun. 2026.
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