1
as in infidelity
lack of faithfulness especially to one's husband or wife
he eventually forgave his wife's unfaithfulness
Synonyms & Similar Words
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Antonyms & Near Antonyms
2
as in betrayal
the act or fact of violating the trust or confidence of another
the jaw-dropping unfaithfulness of the person she had considered her best friend was deeply hurtful
Synonyms & Similar Words
Antonyms & Near Antonyms
3
as in adultery
a sexual encounter or relationship between a married person and someone other than their spouse
there were charges of unfaithfulness on both sides
Synonyms & Similar Words
Antonyms & Near Antonyms
Example Sentences
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Recent Examples of unfaithfulness
Harbour also recently made headlines following the release of estranged wife Lily Allen's latest album, West End Girl, which contained references many interpreted as pointing toward alleged unfaithfulness on Harbour's part, though the actor isn't explicitly named in the lyrics.
—
Joey Nolfi, Entertainment Weekly, 7 Nov. 2025
Milvia Marigliano is a hoot as Coco Vulori, an old dear friend with some very loud opinions to express, and maybe the key to helping DeSantis solve his wife’s onetime unfaithfulness.
—Pete Hammond, Deadline, 27 Aug. 2025
Joey Nolfi, Entertainment Weekly, 7 Nov. 2025
Milvia Marigliano is a hoot as Coco Vulori, an old dear friend with some very loud opinions to express, and maybe the key to helping DeSantis solve his wife’s onetime unfaithfulness.
—Pete Hammond, Deadline, 27 Aug. 2025
Recent Examples of Synonyms for unfaithfulness
Noun
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The Woods brand was badly dinged by his November 2009 car crash and infidelity scandal, but sponsors returned for the comeback story, including his 2019 Masters title.—
Kurt Badenhausen,
Sportico.com,
30 Dec. 2025
-
There has been rumored infidelity aimed at both parties in addition to other grievances.—
Elizabeth Ayoola,
Essence,
29 Dec. 2025
Noun
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Power and crime spark betrayal, forcing him to choose loyalty or survival.—
Marta Balaga,
Variety,
15 Jan. 2026
-
Pic follows the relentless greed of the Fairbank family and their associates who fuel betrayal and murder in the battle for succession.—
Anthony D'Alessandro,
Deadline,
14 Jan. 2026
Noun
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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
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The initial batch of documents showed that Angela Paxton sought the divorce on the grounds that Ken Paxton had committed adultery, but included no additional details.—
S.E. Jenkins,
CBS News,
19 Dec. 2025
Noun
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With season 4 rapidly approaching, now's the time to prepare for the treachery to come.—
Randall Colburn,
Entertainment Weekly,
22 Dec. 2025
-
Instead of being killed, Ashur takes Spartacus’ life and is consequently rewarded for his treachery by the Roman Empire.—
Aramide Tinubu,
Variety,
1 Dec. 2025
Noun
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Its investigative arm reviews officer misconduct complaints, and is expected to one day replace the police department’s internal affairs division.—
Shomik Mukherjee,
Mercury News,
9 Jan. 2026
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The panel assessed the LAPD’s handling of discipline, misconduct complaints, excessive force by officers and other issues.—
David Zahniser,
Los Angeles Times,
9 Jan. 2026
Noun
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Rumors of treason, incompetence and betrayal swirled.—
Antonio María Delgado,
Miami Herald,
8 Jan. 2026
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His Administration has also accused political rivals, including Democratic lawmakers and former President Barack Obama, of sedition and treason.—
Chad de Guzman,
Time,
10 Dec. 2025
Noun
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Instead, tax enforcement has been starved, and large-scale cheating has proliferated.—
Washington Post,
Washington Post,
8 Jan. 2026
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The process seems to be amicable; there was no cheating or abuse.—
Jeanne Phillips,
Mercury News,
6 Jan. 2026
Cite this Entry
“Unfaithfulness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unfaithfulness. Accessed 16 Jan. 2026.
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