adul·​tery ə-ˈdəl-t(ə-)rē How to pronounce adultery (audio)
plural adulteries
: voluntary sexual intercourse between a married person and someone other than that person's current spouse or partner
also : an act of adultery

Did you know?

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 Laws criminalizing adultery are on the books in a handful of other states but are rarely enforced. Kim Bellware, Washington Post, 23 Mar. 2024 The Ten Commandments are fundamental religious tenets in Christianity and Judaism that include edicts not to murder, steal or commit adultery, as well as to have no other gods and to keep the Sabbath holy. The Arizona Republic, 26 Feb. 2024 Many states banned it entirely, while others permitted it only under limited circumstances – typically cruelty, desertion or adultery. Marcia Zug, The Conversation, 21 Mar. 2024 Intended to ensure morally acceptable moviemaking, the code’s long list of prohibitions would include homosexuality, interracial relationships, adultery and overly passionate kisses. Dan Barry, New York Times, 15 Mar. 2024 At one point on their journey, Pema and Karma pass by a village where another woman accused of adultery is forced to shoot an arrow at a bullseye in order to prove her innocence. Jordan Mintzer, The Hollywood Reporter, 23 Feb. 2024 Their parents navigate the corruption plaguing the country as much as the issues roiling their households, like heavy drinking and adultery. Elian Peltier, New York Times, 10 Feb. 2024 Allan helped devise the plan of accusing Jamie (Sam Heughan) of adultery and impregnating Malva, but Malva felt unable to betray Claire in such a way. Maureen Lee Lenker,, 24 June 2023 My divorce has been filed on the grounds of adultery. Jeanne Phillips, The Mercury News, 3 Jan. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'adultery.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


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

First Known Use

15th century, in the meaning defined above

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

Dictionary Entries Near adultery

Cite this Entry

“Adultery.” Dictionary, Merriam-Webster, Accessed 17 May. 2024.

Kids Definition


adul·​tery ə-ˈdəl-t(ə-)rē How to pronounce adultery (audio)
plural adulteries
: voluntary sexual intercourse between a married person and someone other than his or her spouse

Legal Definition


: 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
adulterer noun
adulteress noun

More from Merriam-Webster on adultery

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