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

So far, Loren has dropped several bombshells on Faith, including his STD diagnosis and his infidelity. —Liza Esquibias, People.com, 17 Dec. 2024

Busting 3 common myths about infidelity Clinical psychologist Talal Alsaleem has helped hundreds of couples work through romantic affairs. —Malaka Gharib, NPR, 16 Dec. 2024

Everyone’s various infidelities and fights reach boiling point, with Karl and Orson coming to blows at the Christmas block party, Dylan discovering her mother has been lying to her, and Lynette attempting to apologize to Gaby and Carlos for suing them. —Marianne Eloise, Vulture, 11 Dec. 2024

Shortly after, however, unverified rumors began circulating on social media, including an anonymous tipster suggesting infidelity involving an TikTok influencer. —Jenzia Burgos, StyleCaster, 7 Dec. 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