Definition and pronunciation
infidelity /ˌɪnfɪˈdɛlɪti/ — noun: unfaithfulness in a romantic or marital relationship. It usually refers to violating agreed boundaries (sexual, emotional, or other) with someone outside the relationship.
Easy explanation
Infidelity means breaking the trust of your partner. It can be sexual (sleeping with someone else), emotional (secret romantic attachment), or even financial (hiding money or debts).
Grammatical formation
- Part of speech: usually an uncountable noun (“Infidelity can harm trust”); countable in the sense of instances (“several infidelities”).
- Related forms: infidelities (plural), unfaithful (adjective), to cheat (on) (verb), betrayal (noun).
- Typical verbs: commit, admit (to), conceal, discover, suspect, forgive, condone, confront.
Meanings and nuances
- Sexual or romantic unfaithfulness in a committed relationship.
- Emotional infidelity: intimate, secret connection that undermines the primary bond.
- Financial infidelity: undisclosed spending, debt, or accounts that violate agreed transparency.
- Context matters: in open or polyamorous relationships, behavior is “infidelity” only when it breaks the rules the partners agreed on.
With prepositions and variants
- infidelity to someone: formal/literary (“infidelity to one’s spouse”).
- infidelity in a marriage/relationship: situational context.
- infidelity with someone: the outside person involved (“infidelity with a coworker”).
- admit to infidelity / confess to infidelity: acknowledging the act.
- accuse of infidelity: making an allegation.
Common collocations
commit infidelity; emotional infidelity; sexual infidelity; suspected infidelity; accusations of infidelity; evidence of infidelity; history of infidelity; pattern of infidelities; infidelity in marriage; infidelity in long-distance relationships; financial infidelity; deal with infidelity; recover from infidelity; infidelity counseling; forgive infidelity; zero-tolerance for infidelity
Idioms and neighboring expressions
cheat on someone; have an affair; two-time; step out; stray; fool around; be untrue; play away (BrE); a fling; extramarital affair; betray someone’s trust; break faith
Word comparisons
- infidelity vs adultery: adultery is specifically sexual infidelity within a marriage (often a legal term); infidelity can be sexual or emotional and may apply to unmarried couples.
- infidelity vs cheating: near-synonyms; cheating is more informal.
- infidelity vs unfaithfulness: stylistic variants; unfaithfulness is slightly more formal.
- infidelity vs polyamory/open relationship: consensual non-monogamy isn’t infidelity when boundaries are honored; it becomes infidelity only if agreements are violated.
- infidelity vs betrayal: betrayal is broader; infidelity is one kind of betrayal in intimate relationships.
Real-life examples
- “After discovering messages, they discussed whether it was emotional infidelity.”
- “Financial infidelity—hidden credit cards—nearly ended their marriage.”
- “In their open relationship, secrecy (not outside partners) would count as infidelity.”
Sample sentences
- “He admitted to infidelity and started counseling.”
- “They consider secret dating apps a form of infidelity.”
- “The couple worked through emotional infidelity with clear boundaries.”
- “Accusations of infidelity damaged the public figure’s reputation.”
- “Financial infidelity can be as harmful as a physical affair.”
- “She forgave one infidelity but set firm limits.”
- “Trust is hard to rebuild after infidelity.”
- “They defined infidelity in their prenup to avoid ambiguity.”
- “Rumors of infidelity circulated after the photos were leaked.”
- “He denied any infidelity and offered to share his messages.”
Synonyms
cheating, unfaithfulness, adultery, betrayal, two-timing, philandering, straying, duplicity, perfidy, treachery, affair
Antonyms
fidelity, faithfulness, loyalty, devotion, monogamy, honesty, transparency
Related terms
affair, adultery, emotional affair, micro-cheating, open relationship, consensual non-monogamy (CNM), polyamory, monogamy, jealousy, trust, betrayal trauma, reconciliation, divorce, separation, prenup, postnup, infidelity clause, alienation of affection (jurisdiction-specific), counseling, therapy
Connection to sexuality
Infidelity often involves sexual behavior, but the word itself means breaking agreed relationship boundaries. It can be sexual, emotional, or financial. What counts as infidelity depends on the couple’s explicit or implicit agreements.
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