infidelity
C1formal
Definition
Meaning
The act or fact of being unfaithful to a sexual partner, especially a spouse; marital disloyalty.
Lack of adherence or faithfulness to a person, cause, belief, or principle; betrayal of trust.
Linguistics
Semantic Notes
Primarily associated with sexual/marital betrayal, but can be used metaphorically in other contexts (e.g., political, artistic). The word carries a strong moral judgment.
Dialectal Variation
British vs American Usage
Differences
No significant difference in core meaning. The term 'adultery' is more specific and legalistic, while 'infidelity' is broader and more common in general discourse in both varieties.
Connotations
Equally strong negative connotations in both cultures. Slightly more likely to appear in tabloid/news headlines in UK usage (e.g., 'MP's infidelity scandal'), while US media may also use 'affair' or 'cheating' more frequently in informal contexts.
Frequency
Similar frequency in written and formal spoken contexts. Colloquially, 'cheating' is far more common in both varieties.
Vocabulary
Collocations
Grammar
Valency Patterns
infidelity (to sb/sth)infidelity (towards sb/sth)infidelity (of sb)Vocabulary
Synonyms
Strong
Neutral
Weak
Vocabulary
Antonyms
Phrases
Idioms & Phrases
- “A little infidelity may be forgiven, but never a little indiscretion. (proverbial)”
Usage
Context Usage
Business
Rare. Could be used metaphorically: 'The CEO's infidelity to the company's founding principles caused the crisis.'
Academic
Common in psychology, sociology, and literature studies discussing relationships, trust, and betrayal.
Everyday
Primarily in discussions of personal relationships, news stories, and advice columns. The simpler 'cheating' is more frequent in casual conversation.
Technical
Used in legal contexts (divorce proceedings), marriage counselling, and psychological diagnoses (as a factor in relational trauma).
Examples
By Part of Speech
verb
British English
- N/A - No direct verb form. Use 'be unfaithful' or 'commit infidelity'.
American English
- N/A - No direct verb form. Use 'cheat on' or 'be unfaithful to'.
adverb
British English
- infidelitously (extremely rare, not recommended)
American English
- unfaithfully
adjective
British English
- infidelitous (rare, formal)
American English
- unfaithful (common)
- adulterous (legal/formal)
Examples
By CEFR Level
- The film is about a marriage destroyed by infidelity.
- She discovered his infidelity and was very upset.
- The politician's career never recovered after the revelations of his infidelity.
- Therapy can sometimes help couples rebuild trust after an act of infidelity.
- The novel explores the psychological motivations behind serial infidelity, framing it not as lust but as a profound fear of intimacy.
- His literary infidelity to the original text—taking liberties with the plot and characters—angered the purists.
Learning
Memory Aids
Mnemonic
Think of the word 'FIDELITY' on a high-quality speaker, meaning faithfulness to the original sound. 'INFIDELITY' is the opposite – a broken promise, like a distorted signal.
Conceptual Metaphor
INFIDELITY IS A BREACH OF CONTRACT / INFIDELITY IS A STAIN (on the relationship).
Watch out
Common Pitfalls
Translation Traps (for Russian speakers)
- Do not confuse with 'неверность', which can also mean 'inaccuracy'. Context is key. 'Infidelity' is strictly about betrayal, not a simple mistake.
- The Russian word 'измена' is a closer match, but carries broader meanings (treason, betrayal of country). 'Infidelity' is narrower, primarily romantic/sexual.
Common Mistakes
- Using 'infidelity' to mean 'lack of belief' (confusion with 'infidel').
- Incorrect: 'His infidelity to the details was problematic.' Correct: 'His inattention to detail...'
- Treating it as a countable noun for a single act: 'He had an infidelity' is less common than 'He committed an act of infidelity' or 'He was unfaithful'.
Practice
Quiz
In which context is the metaphorical use of 'infidelity' LEAST appropriate?
FAQ
Frequently Asked Questions
Not exactly. 'Adultery' is a specific legal and religious term for voluntary sexual intercourse between a married person and someone who is not their spouse. 'Infidelity' is broader, encompassing emotional affairs, online relationships, and other betrayals of trust that may not involve sexual intercourse.
Yes, but this is a metaphorical or extended use. It describes a serious breach of faith or principle, e.g., 'The biographer was accused of infidelity to the historical facts.' This usage is more literary or formal.
In casual conversation, 'cheating' is by far the most common term. 'Infidelity' is used in more formal writing, news reports, or therapeutic/legal discussions.
No. You cannot 'infidelity' someone. The corresponding verbal phrases are 'to be unfaithful (to)', 'to cheat (on)', or 'to commit infidelity'.