in·fi·del·i·ty | \ ˌin-fə-ˈde-lə-tē , -(ˌ)fī- \
plural infidelities

Definition of infidelity 

1a : the act or fact of having a romantic or sexual relationship with someone other than one's husband, wife, or partner

b : unfaithfulness to a moral obligation : disloyalty

2 : lack of belief in a religion

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Examples of infidelity in a Sentence

She was convinced that her husband was guilty of infidelity. He has admitted to a number of marital infidelities.

Recent Examples on the Web

Rumors of Prince Charles’s infidelity were widespread, and the pair divorced in 1996. Vogue, "The 20 Most Memorable Royal Weddings of All Time," 11 May 2018 But according to Fields, avoiding infidelity is primarily a matter of both being aware and keeping your partner in the loop. Deanna Pai, The Cut, "The Biggest Findings From a New Study on People Who Cheat," 11 Apr. 2018 The American Psychological Association reports that infidelity in marriages is the cause of 20-40 percent of divorces in the United States. Eric Schiffer, Newsweek, "Should Melania Leave Trump? President's Alleged Infidelity Could Boost the First Lady's Brand," 7 Mar. 2018 There were tabloid tales about his outsize ego, his gambling, his flagrant infidelities. Angelica Baker, Vogue, "Going One-on-One with Greatness at Michael Jordan’s Summer Camp," 13 July 2018 Scenario 2: Kathleen, furious after discovering evidence of her husband’s infidelity with a series of men, confronted Michael., "Candace Zamperini Is The Staircase's Most Polarizing Figure," 15 June 2018 In its opening sequence, Salandar saves a woman from the fists of her abusive CEO boyfriend, hanging him up by his legs and revealing his infidelity and violent history—all while depositing his assets into the bank accounts of his victims. Julie Kosin, Harper's BAZAAR, "The Girl In The Spider’s Web," 7 June 2018 But other reasons included making others jealous and making cheating partners regret their infidelities. Michael Weigold,, "Selfie psychology: Would you risk your life for a photo?," 9 May 2018 Two more collaborations followed in 2017, Claire's Camera and The Day After, both of which center on infidelity. Ben Sachs, Chicago Reader, "Hong Sang-soo and Kim Min-hee's real-life affair yields a trio of films about infidelity," 12 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'infidelity.' 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 infidelity

15th century, in the meaning defined at sense 2

History and Etymology for infidelity

Middle English infidelite, borrowed from Middle French infidelité, borrowed from Latin infidēlitāt-, infidēlitās "faithlessness, inconstancy," from infidēlis "unfaithful, disloyal" + -itāt-, -itās -ity — more at infidel entry 2

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Last Updated

10 Sep 2018

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

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