adul·​tery | \ə-ˈdəl-t(ə-)rē \
plural adulteries

Definition of adultery 

: voluntary sexual intercourse between a married person and someone other than that person's current spouse or partner also : an act of adultery

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Synonyms & Antonyms for adultery


cheating, infidelity, two-timing, unfaithfulness


faithfulness, fidelity

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What’s the difference between adultery and fornication?

In case you were wondering, the words adultery and adult are not etymologically related (in other words, adultery didn’t grow out of adult in the way that punditry grew out of pundit). Although both words come from Latin and share the same first five letters, adultery is from adulterāre (“to pollute, defile, commit adultery”), a word formed ultimately from the Latin elements ad- “to, near” and alter “other.” English adult comes from adultus, which is the past participle of the Latin word adolescere (“to grow up”).

In legal use there is a difference between adultery and fornication. Adultery is only used when at least one of the parties involved (either male or female) is married, whereas fornication may be used to describe two people who are unmarried (to each other or anyone else) engaging in consensual sexual intercourse.

Examples of adultery in a Sentence

He found out that his wife had committed adultery. She accused her husband of adultery.

Recent Examples on the Web

In 1536, Anne Boleyn, second wife of King Henry VIII, was arrested and charged with adultery; she was beheaded 17 days later., "This day in history," 2 May 2018 Steven and Katie were arrested Jan. 27 and charged with adultery and contributing to delinquency. Fox News, "North Carolina incest father told mother he killed daughter-wife and their child in shocking 911 call," 13 Apr. 2018 If a man's sperm fertilizes an egg from a woman who is not his wife, does that constitute adultery? Ariana Eunjung Cha,, "40 years after 1st 'test tube' baby, science has produced 7 million babies - and raised moral questions," 27 Apr. 2018 Aside from legal implications, not fasting is a major sin, worse than adultery or drunkenness in Islam. Ashley May, USA TODAY, "Why are Muslims fasting? What you need to know about Ramadan," 11 May 2018 The couple’s relationship has been rocky after it was revealed that Josh was unfaithful to his wife and used adultery site Ashley Madison to cheat. Kathleen Joyce, Fox News, "Anna Duggar says 'past 10 years' with husband Josh Duggar 'have been a wonderful adventure'," 6 July 2018 The late Sheikh Abdelaziz Bin Baz, the kingdom’s top official cleric, opined that women should stay at home to reduce the risk of adultery. The Economist, "Saudi women want more sway in religious affairs," 12 July 2018 One of them said, the sixth commandment is, thou shalt not admit adultery. Harry Bruinius, The Christian Science Monitor, "In Plains, Ga., an evangelical politician like no other," 11 July 2018 Written by Jessie Nelson, composed by Sara Bareilles, and based on the 2007 movie starring Keri Russell, Waitress is a sweet-as-pie musical about domestic abuse and adultery. Tony Adler, Chicago Reader, "In the world of Waitress, almost all sins can be forgiven with a song," 11 July 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'adultery.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of adultery

15th century, in the meaning defined above

History and Etymology for adultery

Middle English adultrye, adultery, alteration (conformed to Latin adulterium) of avoutrie, advoutrie, alteration (with addition of suffix -ie -y entry 2) of avoutre, borrowed from Anglo-French avulteire, avouteire, going back to Latin adulterium, from adulterāre "to defile by adultery, commit adultery with, pollute" + -ium deverbal noun suffix — more at adulterate entry 1

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Statistics for adultery

Last Updated

2 Oct 2018

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Time Traveler for adultery

The first known use of adultery was in the 15th century

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More Definitions for adultery



English Language Learners Definition of adultery

: sex between a married person and someone who is not that person's wife or husband


adul·​tery | \ə-ˈdəl-tə-rē\

Legal Definition of adultery 

: voluntary sexual activity (as sexual intercourse) between a married man and someone other than his wife or between a married woman and someone other than her husband also : the crime of adultery — compare fornication

Other Words from adultery

adulterer \ ə-​ˈdəl-​tə-​rər \ noun
adulteress \ -​tə-​rəs \ noun

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Comments on adultery

What made you want to look up adultery? Please tell us where you read or heard it (including the quote, if possible).


playful or foolish behavior

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