infidelity

[in-fi-del-i-tee]

noun

plural

infidelities 

1. marital disloyalty; adultery.

2. unfaithfulness; disloyalty.

3. lack of religious faith, especially Christian faith.

4. a breach of trust or a disloyal act; transgression.

infidelity

/ ˌɪnfɪˈdɛlɪtɪ /

noun

1. lack of faith or constancy, esp sexual faithfulness

2. lack of religious faith; disbelief

3. an act or instance of disloyalty

Word History and Origins

Origin of infidelity¹

First recorded in 1375–1425; late Middle English, from Latin infidēlitās; equivalent to infidel + -ity

Example Sentences

His 1968 version of “I Heard It Through the Grapevine,” a song about a man tormented by rumors of his lover’s infidelity, was a No. 1 hit.

From Los Angeles Times

The couple were engaged for a time, but the relationship fell apart in 2015 amid a flurry of press speculation, including allegations of Malik's infidelity.

From BBC

The judges highlighted longstanding marital discord, with the couple living apart and Mamta suspecting her husband of infidelity.

From BBC

A pop psychologist would say witnessing his dad’s infidelity triggered Isaac’s fear of commitment.

From Los Angeles Times

We’ve found a new bad decision to rule the season, and it’s infidelity.

From Salon

Related Words

• adultery 
• affair 
• betrayal 
• duplicity 
• treachery