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
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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Otake said Gerhardt Konig was not someone who would try to commit murder, but someone who was struggling with infidelity and trying to do his best.—
ABC News,
ABC News,
8 Apr. 2026
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Tensions notably come to a head between Bennie and his sister-in-law, Lucretia (a game Wanda Sykes), because of his past infidelity, which provides some of the sitcom's funniest moments via razor-sharp one-liner wars.—
Andrew Walsh,
Entertainment Weekly,
5 Apr. 2026
Noun
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Whether a Black woman can be afforded the same narrative elasticity as her peers after a betrayal, and be reactive yet sympathetic without her identity becoming the factor that defines how all of it is judged, remains to be seen.—
Shamira Ibrahim,
HollywoodReporter,
8 Apr. 2026
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These are bonds far stronger than the buzz of the last deal or the fizz of the last party; both loyalties and betrayals are rooted in decades of intimate connection.—
Michael Sheridan,
Vanity Fair,
8 Apr. 2026
Noun
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The Bible teaches that lying, stealing, adultery and coveting your neighbor’s property are sins.—
Sun Sentinel Editorial Board,
Sun Sentinel,
16 Mar. 2026
-
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
Noun
-
Undocumented immigrants venture from Mexico, often underestimating of the treachery of the landscape.—
Shi En Kim,
AZCentral.com,
26 Mar. 2026
-
Jonathan Cute kept probing the murky realms between tourism and treachery.—
Adam Ciralsky,
Vanity Fair,
19 Mar. 2026
Noun
-
Ortega said she was motivated to introduce AB 2321 because of what the auditor reported about Cal-OSHA’s Bureau of Investigation, the unit responsible for investigating death and career-ending injuries for criminal misconduct.—
Joe Rubin,
Sacbee.com,
6 Apr. 2026
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The news that someone was seen with him has, of course, been received with a lot of interest, particularly considering that since his arrest for suspicion of misconduct in public office, neither his ex, Sarah Ferguson, nor his daughters, Princess Eugenie and Princess Beatrice, have visited him.—
Lizzie Lanuza,
StyleCaster,
6 Apr. 2026
Noun
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Consider this evilmeister’s brazen acts of treason and revenge, unbounded deceit, swinish immorality and negative role modeling.—
Voice of the People,
New York Daily News,
5 Apr. 2026
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She was imprisoned in Salimgarh Fort (a part of Red Fort) in Delhi by her father for more than 20 years for inciting her brother, Muhammad Akbar, to commit treason.—
Tamanna Nangia,
Encyclopedia Britannica,
2 Apr. 2026
Noun
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Time and again, the panel of experts invited to provide testimony said voter fraud is exceedingly rare and that there is no evidence of widespread cheating.—
Linh Tat,
Daily News,
8 Apr. 2026
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Though outright cheating does not go unpunished, contestants are often rewarded for finding loopholes in the rules and exploiting them.—
Encyclopedia Britannica,
Encyclopedia Britannica,
8 Apr. 2026
Cite this Entry
“Unfaithfulness.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unfaithfulness. Accessed 11 Apr. 2026.
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