[ uh-duhl-ter-uhs ]
/ əˈdʌl tər əs /
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characterized by or involved in adultery; illicit: an adulterous relationship.
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Origin of adulterous

1400–50; adulter(y) + -ous; replacing late Middle English avoutrious


a·dul·ter·ous·ly, adverbun·a·dul·ter·ous, adjectiveun·a·dul·ter·ous·ly, adverb
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2023


What does adulterous mean?

Adulterous is used to describe a person who engages in or a relationship that constitutes adultery—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, adultery 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 adulterous, 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 adulterous. In some cases, a relationship may even be considered adulterous when it’s nonsexual but intimate (this is sometimes called an emotional affair).

The words adultery and adulterous are especially used in a religious context, in which adultery is often considered a sin. The word adultery is also sometimes used in a legal context, such as during divorce proceedings.

Adultery is associated with a considerable amount of stigma. The word adulterous is always used negatively and implies a critical judgment of such actions.

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

Example: Just because it only happened once doesn’t mean it wasn’t adulterous.

Where does adulterous come from?

The first records of the word adulterous come from the 1400s. Its base word, adultery, 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, calling a person or a relationship adulterous typically means that at least one of the partners is married.

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What are some other forms related to adulterous?

What are some synonyms for adulterous?

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


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

What are some words adulterous may be commonly confused with?

How is adulterous used in real life?

Adulterous is typically used in a judgmental way.

How to use adulterous in a sentence

British Dictionary definitions for adulterous

/ (əˈdʌltərəs) /

of, characterized by, or inclined to adultery
an obsolete word for adulterate (def. 2)

Derived forms of adulterous

adulterously, adverb
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