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
Synonyms & Similar Words
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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Kate divorced Jon, 48, in 2009 amid reports of infidelity surrounding her now ex-husband.
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Skratch also interviewed other sources for its story who alleged infidelity by Mickelson amid abrupt endings of memberships at other golf clubs.
Noun
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This is not treachery but the truest and noblest affection.
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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.
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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In movies, friendships end with a big blowup after there has been a significant betrayal by one party.
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Whether discussing policing, immigration, criminal justice or foreign policy, compromise is treated as betrayal.
Noun
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And still, some people insist that admitting the flaws in our history — and our present — constitutes an act of innate disloyalty.
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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.
Noun
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What constitutes treason is emerging as an early theme of House of the Dragon’s third season.
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His attorney, Erias Lukwago, was taken from his house and later charged with an offense related to the concealment of treason.
Cite this Entry
“Perfidy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/perfidy. Accessed 5 Jul. 2026.
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