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
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Antonyms & Near Antonyms
Example Sentences
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Recent Examples of unfaithfulness
According to The Daily Mail, unfaithfulness might have been the cause.
—
Lizzie Lanuza, StyleCaster, 12 Jan. 2026
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
Lizzie Lanuza, StyleCaster, 12 Jan. 2026
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
Recent Examples of Synonyms for unfaithfulness
Noun
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All the secrets pour out, the revelations of infidelity and addiction and so on, as the group gives vent to the stuff that’s previously been unsayable—not to fix anything, mind you, since some things can’t be fixed.—
Emily Nussbaum,
New Yorker,
12 Mar. 2026
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These liaisons are consensual but fraught by infidelity, disparities in age and power, shifting norms.—
Judy Berman,
Time,
5 Mar. 2026
Noun
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There are some broadly entertaining yet scattershot series of betrayals, shootouts, car chases (and subsequent crashes), though little that actually raises the pulse or grabs your emotions.—
Chase Hutchinson,
IndieWire,
19 Mar. 2026
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From church pulpits to community gatherings, the policy U-turn was widely viewed as a betrayal of Black Americans who had propped up the retail giant's fortunes.—
Jessica Guynn,
USA Today,
18 Mar. 2026
Noun
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The facile novelty of adultery is its own mask, a sexy way of dressing up a deep, frightened longing for security.—
Sara Holdren,
Vulture,
6 Mar. 2026
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The Texas attorney general beat a 2023 impeachment trial on corruption charges and reached a deal to end a long-running securities fraud case but now faces a contentious divorce over allegations of adultery.—
Meg Kinnard,
Chicago Tribune,
17 Feb. 2026
Noun
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Not having to bear that burden, I was transported by Bentley and his co-writer Greg Kwedar to a Pacific Northwest of quiet beauty and matter-of-fact treachery.—
Joe Reid,
Vulture,
10 Mar. 2026
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After Thomas Hickey was hanged that year for mutiny, sedition and treachery, Washington warned that his fate should serve as a caution to all soldiers.—
Kim Hjelmgaard,
USA Today,
26 Feb. 2026
Noun
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Their first trial had ended in a hung during, and the second has been delayed twice as an investigation grows around alleged misconduct from a State Police officer who investigated their case.—
Colleen Cronin,
Boston Herald,
16 Mar. 2026
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Democrats have sought to require body cameras and judicial warrants for arrests, forbid the use of masks and expand the ability to sue DHS for alleged misconduct.—
Bloomberg Wire,
Dallas Morning News,
16 Mar. 2026
Noun
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Pavel Dabravolski, a 36-year-old Belarusian journalist for BelaPAN, was sentenced to nine years in a maximum-security prison after being convicted of treason, according to the Belarusian Association of Journalists.—
Arkansas Online,
Arkansas Online,
13 Mar. 2026
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Current law says only those accused of murder or treason can have bail withheld, but this language expands that possibility to other offenses, such as misdemeanors.—
Kayla Dwyer,
IndyStar,
6 Mar. 2026
Noun
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Grohl refused to answer additional questions about his cheating, instead suggesting that the Foo Fighters’ upcoming album contains songs and lyrics that allude to it.—
Devon Ivie,
Vulture,
20 Mar. 2026
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The cheating isn’t new, this argument goes; it’s just getting discovered and prosecuted more frequently.—
McKay Coppins,
The Atlantic,
12 Mar. 2026
Cite this Entry
“Unfaithfulness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unfaithfulness. Accessed 21 Mar. 2026.
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