Definition and pronunciation
adultery — noun: sexual relations between two people when at least one is married to someone else; used in legal, journalistic, and religious contexts.
Pronunciation: /əˈdʌl.tə.ri/ (US/UK).
Easy explanation
Adultery means a married person has sex with someone who is not their spouse. Many people also use it to mean a sexual affair during a committed, exclusive relationship.
Part of speech and grammar
- Noun (usually uncountable): commit adultery; accused of adultery.
- Rare plural (legalistic): adulteries.
- Word family: adulterous (adj.), adulterer/adulteress (gendered nouns; many prefer neutral “unfaithful spouse/partner”).
- Typical frames: allegation of adultery; grounds for divorce; adulterous relationship.
Register and tone
Neutral-to-formal but often morally charged. Common in law, religious writing, and careful journalism. In everyday speech, people say cheat/cheating or have an affair.
Connection to sexuality
Direct. It names consensual sexual activity that violates an exclusivity commitment (marital or, by extension, a declared exclusive partnership). It does not describe non-consensual acts, which should be named separately (e.g., sexual assault).
Common collocations
commit adultery; adulterous affair; adulterous spouse; allegation of adultery; grounds for divorce; prove adultery; criminal adultery (in some jurisdictions); extramarital affair; adulterous conduct; confession of adultery.
Idioms and set phrases
- in adultery — archaic/legal phrasing (caught in adultery).
- act(s) of adultery — formal legal phrase.
- fornicators and adulterers — stock pairing in religious texts.
Prepositions and meaning shifts
- adultery with [person] — names the partner outside the marriage.
- adultery against [spouse] — emphasizes betrayal of the spouse (less common).
- adultery by [party] — legal phrasing identifying the accused.
- adultery under [law/doctrine] — ties it to a rule system.
Note: “adultery on [someone]” is nonstandard; use cheat on.
Word comparisons
- adultery vs fornication — adultery: at least one married partner; fornication: historically sex between unmarried people.
- adultery vs infidelity — infidelity can be sexual or emotional; adultery usually implies sexual conduct.
- adultery vs affair — affair can be romantic and ongoing (often sexual); adultery focuses on the violation itself.
- adultery vs cheating — cheating is the everyday term; may include nonsexual deceit.
- adultery vs bigamy — bigamy is marrying another person while already married.
- adultery vs open relationships/polyamory — with consent and agreements, these are not adultery.
Real-life examples
- The petition cited adultery as grounds for divorce.
- Some faith communities discipline leaders after confirmed adultery.
- A few places still criminalize adultery; elsewhere it’s only a civil matter relevant to divorce.
- Reporters avoided speculation and referred to “alleged adultery” pending confirmation.
Sample sentences
- The court found no evidence of adultery and dismissed the claim.
- She described the relationship as an affair; the tabloid labeled it adultery.
- Adultery is distinct from assault; consent is the core difference.
- They agreed on an open marriage; sex with others by agreement was not adultery.
- The novel explores guilt and secrecy after an act of adultery.
Synonyms
infidelity, cheating, extramarital sex, extramarital affair, unfaithfulness, two-timing, cuckoldry (archaic), illicit relationship
Antonyms
fidelity, faithfulness, marital loyalty, monogamy, chastity, celibacy, exclusivity
Related terms
fornication, adulterous, adulterer, affair, betrayal, divorce, separation, reconciliation, prenuptial agreement, alienation of affection, bigamy, polygamy, open relationship, consensual non-monogamy, consent, marital vows
Notes and etiquette
Use precise language: distinguish consensual adultery (a breach of commitment) from crimes involving lack of consent. Avoid gendered slurs; if clarity matters, specify whether you mean a civil issue in divorce law or a religious/ethical judgment. Laws and definitions vary by jurisdiction.
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