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 husband, wife, or partner

b

: unfaithfulness to a moral obligation : disloyalty

2

: lack of belief in a religion

Synonyms

• disloyalty
• faithlessness
• falseness
• falsity
• inconstancy
• perfidiousness
• perfidy
• unfaithfulness

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

However, the letter did not mention Stallone's infidelity with supermodel Janice Dickinson, which Flavin later discovered. —Jason Fields, Newsweek, 5 Dec. 2024

The wife of Charles II, whose ascension to the throne in 1660 marked the restoration of the British monarchy after the upheaval of civil war, Catherine is remembered, when she is remembered at all, for enduring her husband’s infidelity and the elevation of his many mistresses. —Meilan Solly, Smithsonian Magazine, 27 Nov. 2024

Despite their vigorous and sustained efforts, intense seekers often face severe challenges like mental health struggles, excessive conflict and issues such as infidelity, substance abuse or disagreements over finances or housework in their marriages. —Mark Travers, Forbes, 24 Nov. 2024

The show became a massive hit, but eventually, Ball couldn't abide Arnaz's infidelities. —Maureen Lee Lenker, EW.com, 20 Nov. 2024

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

Kids 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