un·​faith·​ful | \ ˌən-ˈfāth-fəl How to pronounce unfaithful (audio) \

Definition of unfaithful

: not faithful:
a : not adhering to vows, allegiance, or duty : disloyal an unfaithful friend
b : not faithful to marriage vows suspected her husband of being unfaithful
c : inaccurate, untrustworthy an unfaithful copy of a document

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Other Words from unfaithful

unfaithfully \ ˌən-​ˈfāth-​fə-​lē How to pronounce unfaithfully (audio) \ adverb
unfaithfulness noun

Examples of unfaithful in a Sentence

colonists who later proved to be unfaithful to the cause of independence
Recent Examples on the Web The suspicious death of Joey (Berg), the unfaithful husband of Sciorra's unhappy character, ups the stakes, but the investigation by De Niro has been abruptly terminated and Freddy's sharp new deputy (Garofalo) high-tails it out of town. David Hunter, The Hollywood Reporter, "'Cop Land': THR's 1997 Review," 15 Aug. 2019 The clergyman is a family friend to whom Mrs. Alving once was (and may still be) attracted but who consigned her to years of misery by persuading her to return to her unfaithful husband. Don Aucoin, BostonGlobe.com, "At Williamstown, Uma Thurman overcomes the challenges of a role — and the production she’s in," 9 Aug. 2019 Later, when he is falsely persuaded that Imogen was unfaithful, Posthumus orders her killed by his servant, Pisanio (Remo Airaldi, excellent as usual). Don Aucoin, BostonGlobe.com, "On the Common, a whimsical ‘Cymbeline’," 25 July 2019 Love Actually, where a 2000 re-recording of the song plays mournfully over Emma Thompson's heart-wrenching discovery that her husband has been unfaithful. Billboard Staff, Billboard, "The 100 Best Songs of 1969: Staff Picks," 14 Aug. 2019 Then the exiled Posthumus is bamboozled into believing Imogen has been unfaithful to him — just part of the welter of schemes, counterschemes, deceptions, disguises, and palace intrigue in the play. BostonGlobe.com, "The Ticket: What’s happening in the local arts world," 18 July 2019 And now, the Bay Area’s fourth-largest city can add to its awards mantle the fifth-place trophy among the most unfaithful cities in the nation. Joseph Geha, The Mercury News, "Fremont ranks as fifth most unfaithful city in the nation on affairs website hotlist," 19 June 2019 In Così fan tutte, however, nobody is punished: the officers lose the wager because the women prove unfaithful, but the opera seems to end happily for everyone. Larry Wolff, The New York Review of Books, "‘Così’ in Coney," 27 Mar. 2018 Despite their apparent passion, Juana's husband Philip was frequently unfaithful to her, his indiscreet affairs causing Juana to fly into rages and periods of depression that provoked the first rumors about Juana's mental state. Lauren Hubbard, Town & Country, "What Was Catherine of Aragon's Sister, Juana la Loca, Really Like?," 10 June 2019

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'unfaithful.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of unfaithful

15th century, in the meaning defined above

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Statistics for unfaithful

Last Updated

15 Oct 2019

Time Traveler for unfaithful

The first known use of unfaithful was in the 15th century

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More Definitions for unfaithful


How to pronounce unfaithful (audio)

English Language Learners Definition of unfaithful

: having a sexual relationship with someone who is not your wife, husband, or partner
: not accurate


un·​faith·​ful | \ ˌən-ˈfāth-fəl How to pronounce unfaithful (audio) \

Kids Definition of unfaithful

: not faithful : disloyal

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Comments on unfaithful

What made you want to look up unfaithful? Please tell us where you read or heard it (including the quote, if possible).


to engage in dissolute behavior

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