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
All that said, Trump’s willingness to forgive the legal sins of former GOP congressman is a notable footnote to an often wretched history of pardon perfidy engaged in by presidents of both parties.
—
David Mark, The Washington Examiner, 31 Oct. 2025
Their perfidy is memorialized in the English language, though.
—Evan Osnos, New Yorker, 26 May 2025
The prior month, Vice President JD Vance had lodged his own complaints about Europe’s alleged perfidy, threatening that the United States might withdraw its security guarantees from Europe if the EU continued to aggressively regulate U.S. tech companies.
—Anu Bradford, Foreign Affairs, 21 Apr. 2025
Despite high trade deficits, the U.S. economy is strong
Trump and his advisers point to America’s lopsided trade numbers—year after year of huge deficits—as proof of foreigners’ perfidy.
—Time, 9 Apr. 2025
See All Example Sentences for perfidy
David Mark, The Washington Examiner, 31 Oct. 2025
Their perfidy is memorialized in the English language, though.
—Evan Osnos, New Yorker, 26 May 2025
The prior month, Vice President JD Vance had lodged his own complaints about Europe’s alleged perfidy, threatening that the United States might withdraw its security guarantees from Europe if the EU continued to aggressively regulate U.S. tech companies.
—Anu Bradford, Foreign Affairs, 21 Apr. 2025
Despite high trade deficits, the U.S. economy is strong
Trump and his advisers point to America’s lopsided trade numbers—year after year of huge deficits—as proof of foreigners’ perfidy.
—Time, 9 Apr. 2025
See All Example Sentences for perfidy
Recent Examples of Synonyms for perfidy
Noun
-
In December, Kristy alleged infidelity as the reason for her split from Desmond, per court records previously obtained by PEOPLE.—
Zoey Lyttle,
PEOPLE,
29 Jan. 2026
-
One couple will discover infidelity.—
Marta Balaga,
Variety,
29 Jan. 2026
Noun
-
Perfidy — from the French perfidie via the Latin perfidia — means deceitfulness, treachery or a breach of faith or promise.—
Harmeet Kaur,
CNN Money,
21 Jan. 2026
-
But despite all this, not every Chelsea fan outside his family will regard this transfer as treachery.—
Simon Johnson,
New York Times,
17 Jan. 2026
Noun
-
Ken Paxton, a Republican running for the Senate, denied the adultery allegations.—
Jane Harper,
Dallas Morning News,
15 Jan. 2026
-
The book presents itself as a comic take on the classic adultery novel and a send-up of a narrow, self-conscious group of downwardly mobile New Yorkers.—
Literary Hub,
Literary Hub,
8 Jan. 2026
Noun
-
It’s filled with super-heightened emotions; unrestrained passion, betrayal, evil and even a magic spell or two.—
David Lyman,
Cincinnati Enquirer,
5 Feb. 2026
-
What’s most striking about the response is the sense of betrayal about Aronofsky’s involvement.—
Jake Kanter,
Deadline,
5 Feb. 2026
Noun
-
Research on group dynamics shows that dissent is often interpreted as disloyalty rather than contribution.—
Benjamin Laker,
Forbes.com,
16 Jan. 2026
-
The courts have warned against treating dissent as disloyalty.—
Chicago Tribune,
Chicago Tribune,
12 Jan. 2026
Noun
-
The president’s team moved quickly to prosecute the sheriff for treason.—
Michael Scherer,
The Atlantic,
22 Jan. 2026
-
Veteran opposition figure Kizza Besigye, a four-time presidential candidate, remains in prison after he was charged with treason last February.—
Los Angeles Times,
Los Angeles Times,
17 Jan. 2026
Cite this Entry
“Perfidy.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/perfidy. Accessed 9 Feb. 2026.
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