infidelity

noun

in·​fi·​del·​i·​ty ˌin-fə-ˈde-lə-tē How to pronounce infidelity (audio)
-(ˌ)fī-
plural infidelities
1
a
: 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

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
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
These include infidelities, unspoken longings, and thorny questions of land inheritance. The New Yorker, New Yorker, 2 June 2025 This places the blame on the victim rather than the perpetrator of infidelity. Mark Travers, Forbes.com, 2 June 2025 In 2023, Korie and Willie produced The Blind, a film about Phil and Kay Robertson that also explores the former's infidelity, alcoholism, and faith journey. Allison Degrushe, EW.com, 31 May 2025 If trapped in a situation involving domestic abuse, spousal infidelity, or romantic coercion, any action a woman takes can be justified or understood. Roxana Hadadi, Vulture, 29 May 2025 See All Example Sentences for infidelity

Word History

Etymology

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

First Known Use

15th century, in the meaning defined at sense 2

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

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Cite this Entry

“Infidelity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infidelity. Accessed 12 Jun. 2025.

Kids Definition

infidelity

noun
in·​fi·​del·​i·​ty ˌin-fə-ˈdel-ət-ē How to pronounce infidelity (audio)
-(ˌ)fī-
plural infidelities
1
: lack of faith in a religion
2
: unfaithfulness especially to one's husband or wife

More from Merriam-Webster on infidelity

Last Updated: - Updated example sentences
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