infidelity
noun
in·fi·del·i·ty
ˌin-fə-ˈde-lə-tē 
-(ˌ)fī-
plural infidelities
1
a
: the act or fact of having a romantic or sexual relationship with someone other than one's spouse or partner
b
: unfaithfulness to a moral obligation : disloyalty
infidelity to the group's guiding principles
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
With whom, by whom, and thanks to whom is of no significance to him whatsoever, so it can hardly be considered infidelity.
—
Agnieszka Szpila, Harpers Magazine, 24 Mar. 2026
Fans were outraged when rumors of infidelity on the Irish actor’s part began to circulate.
—Fleurine Tideman, Glamour, 23 Mar. 2026
Sullivan also accused Morgan’s wife, the journalist and author Celia Walden, of pining for infidelity in her social media posts.
—Jake Kanter, Deadline, 19 Mar. 2026
Josh apologized for marital infidelity and a pornography addiction at the time and sought treatment.
—Brie Stimson, FOXNews.com, 19 Mar. 2026
See All Example Sentences for infidelity
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Agnieszka Szpila, Harpers Magazine, 24 Mar. 2026
Fans were outraged when rumors of infidelity on the Irish actor’s part began to circulate.
—Fleurine Tideman, Glamour, 23 Mar. 2026
Sullivan also accused Morgan’s wife, the journalist and author Celia Walden, of pining for infidelity in her social media posts.
—Jake Kanter, Deadline, 19 Mar. 2026
Josh apologized for marital infidelity and a pornography addiction at the time and sought treatment.
—Brie Stimson, FOXNews.com, 19 Mar. 2026
See All Example Sentences for infidelity
Cite this Entry
“Infidelity.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/infidelity. Accessed 6 Apr. 2026.
Copy CitationKids Definition
infidelity
noun
in·fi·del·i·ty
ˌin-fə-ˈdel-ət-ē
-(ˌ)fī-
plural infidelities
1
: lack of faith in a religion
2
: unfaithfulness especially to one's husband or wife
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