[ uh-duhl-tuh-ree ]
/ əˈdʌl tə ri /
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noun, plural a·dul·ter·ies.
voluntary sexual intercourse between a married person and someone other than their lawful spouse.


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Origin of adultery

1325–75; Middle English adulterie<Latin adulterium, equivalent to adulter (see adulterer) + -ium-ium; replacing Middle English a(d)vouterie<Old French avoutrie<Latin, with ad-ad- replacing aa-5
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does adultery mean?

Adultery is a consensual sexual relationship or encounter between someone who’s married and a person they’re not married to (who may or may not be married to someone else).

In other words, it can be between two people who are both married to other people, or between a married person and a nonmarried person. Typically, for something to be considered adultery, at least one of the partners must be married.

On the other hand, similar words like cheating, infidelity, and unfaithfulness can be used regardless of whether either person is married—they simply refer to a (usually sexual) relationship or encounter between people when one or both of them is in a committed relationship with someone else.

When it happens with someone other than one’s spouse, a long-term relationship (often called an affair), a single sexual encounter, or anything in between can be considered to constitute adultery. In some cases, a relationship may even be considered adultery when it’s nonsexual but intimate (this is sometimes called an emotional affair).

The word adultery is especially used in a religious context, in which it’s often considered a sin. For that reason, it’s often used with the verb commit. It’s also sometimes used in a legal context, such as during divorce proceedings. Adultery is a crime in some places (including in some U.S. states, though people aren’t often charged for it).

Adultery is associated with a considerable amount of stigma. The word adultery and its related terms are always used negatively and imply a critical judgment of such actions.

Someone who participates in adultery can be called an adulterer. Such people or relationships can be described as adulterous. The word adulteress specifically refers to a woman who has engaged in adultery. (It has been more common throughout history for women to be blamed—and punished—for adulterous relationships than men.)

Example: Adultery is a profound breach of trust in a marriage.

Where does adultery come from?

The first records of the word adultery come from the 1300s. It ultimately derives from the Latin verb adulterāre, meaning “to defile.” The same word is the basis of the English verb adulterate, meaning “to debase” or “to make impure.” Adultery involves adults, but the word adult is based on a different root.

“Thou shalt not commit adultery” is one of the Ten Commandments, and adultery is specifically prohibited by multiple religions and even some laws. In the past, adultery was sometimes used in a more general way to refer to any type of sexual activity considered sinful. Today, however, adultery typically means that at least one of the partners is married (whereas the word fornication is often used in a religious context to refer to any sex outside of marriage).

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What are some other forms related to adultery?

What are some synonyms for adultery?

What are some words that share a root or word element with adultery



What are some words that often get used in discussing adultery?


What are some words adultery may be commonly confused with?



How is adultery used in real life.

Adultery is typically used in a judgmental way.



How to use adultery in a sentence

British Dictionary definitions for adultery

/ (əˈdʌltərɪ) /

noun plural -teries
voluntary sexual intercourse between a married man or woman and a partner other than the legal spouse

Word Origin for adultery

C15: adulterie, altered (as if directly from Latin adulterium) from C14 avoutrie, via Old French from Latin adulterium, from adulter, back formation from adulterāre. See adulterate
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012