as in traitorous
not true in one's allegiance to someone or something
colonists who later proved to be unfaithful to the cause of independence
Synonyms & Similar Words
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Antonyms & Near Antonyms
1
as in infidelity
lack of faithfulness especially to one's husband or wife
he eventually forgave his wife's unfaithfulness
Synonyms & Similar Words
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 unfaithful
Amber Harding Outkick, FOXNews.com, 28 Apr. 2026
Upon discovering that her abusive husband (Caleb Landry Jones) had been unfaithful, Becky drove off with her parents' car and shot at the door of his mistress' apartment.
—Drew MacKie, PEOPLE, 11 Apr. 2026
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
See All Example Sentences for unfaithful
Adjective
This story isn't nearly as exciting because an NBA player being unfaithful to his girlfriend sort of just feels like a regular Thursday afternoon.
—Amber Harding Outkick, FOXNews.com, 28 Apr. 2026
Upon discovering that her abusive husband (Caleb Landry Jones) had been unfaithful, Becky drove off with her parents' car and shot at the door of his mistress' apartment.
—Drew MacKie, PEOPLE, 11 Apr. 2026
Noun
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
See All Example Sentences for unfaithful
Recent Examples of Synonyms for unfaithful
Adjective
-
And at the very center of Hell is Satan himself, the traitorous Archangel Lucifer, depicted as a monstrous creature with wings and three heads.—
Keith Cooper,
Space.com,
11 May 2026
-
Russell fabricates a lie with the rest of the villains, and the heroes believe it, despite a warning from one traitorous tribemate.—
Literary Hub,
Literary Hub,
5 Dec. 2025
Noun
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Paxton’s baggage Cornyn’s runoff strategy has leaned heavily on Paxton’s ethical and legal history — the 2023 House impeachment and ongoing scrutiny of his conduct as attorney general and allegations of infidelity in his personal life.—
Fort Worth Star-Telegram,
Fort Worth Star-Telegram,
19 May 2026
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In 1672, Antonia Bembo – then living in the back part of a house known as Cà Bembo in the neighborhood of Santa Maria Nova – sued for divorce, citing Lorenzo’s infidelity along with mental and physical abuse.—
Claire Fontijn,
The Conversation,
18 May 2026
Noun
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But somewhere along the way, a portion of the WNBA ecosystem — fans, players and even some media members — started treating criticism as betrayal.—
Amber Harding OutKick,
FOXNews.com,
14 May 2026
-
The sequel series is based on similar – and familiar – concepts of love, loyalty and betrayal, once again set in the mafia underworld.—
Jesse Whittock,
Deadline,
14 May 2026
Noun
-
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
Adjective
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Broadband coverage is available to about 80 percent of Wakulla County, where Mashes Sands Beach is located, and cell service can be unreliable depending on your exact location.—
Gabi De la Rosa,
Southern Living,
19 May 2026
-
Even with coupons or savings programs, access remained unreliable for many.—
Payton Herres,
STAT,
19 May 2026
Noun
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Upon learning of Ava’s treachery, Deborah HOWLS.—
Jessica M. Goldstein,
Vulture,
1 May 2026
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Inflamed by Ratansen’s adviser’s account of Padmavati’s beauty, Alauddin Khalji storms the fortress by treachery rather than valor.—
Encyclopedia Britannica,
Encyclopedia Britannica,
9 Apr. 2026
Noun
-
The timeline of the Andrew scandal has been heavily discussed, even before the disgraced former prince was arrested for suspicion of misconduct in public office.—
Lizzie Lanuza,
StyleCaster,
17 May 2026
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In December, Hill pleaded guilty to state charges of misconduct, perjury and obstruction of justice and was put on probation.—
N'dea Yancey-Bragg,
USA Today,
15 May 2026
Adjective
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On May 14, Dana Williamson, a former top aide to Newsom and onetime Becerra political adviser, pleaded guilty in federal court after accepting a plea deal to multiple charges, including committing bank and wire fraud, filing a false tax return, and lying to the FBI.—
James Ward,
USA Today,
15 May 2026
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Dana Williamson, former top aide to Newsom, pleaded guilty in an FBI corruption probe to bank fraud, filing a false tax return and lying to the FBI.—
Sacbee.com,
Sacbee.com,
15 May 2026
Cite this Entry
“Unfaithful.” Merriam-Webster.com Thesaurus, Merriam-Webster, https://www.merriam-webster.com/thesaurus/unfaithful. Accessed 22 May. 2026.
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