Other forms: infidelities
Infidelity is betrayal of a partner by secretly taking a lover. Accused of infidelity, marital infidelity, forgive an infidelity.
It applies to any committed couple, married or not, and the secrecy is essential to it — an open arrangement is not infidelity by definition. The word also once meant unbelief, which is where infidel comes from, and that sense has died away.
1nouninfidelityBetrayal of a partner by secretly taking a lover.
“Their marriage ended after she discovered his infidelity with a colleague.”
infidelity is a betrayal.
Latin infidelitas means unfaithfulness — in, not, plus fidelis, faithful, from fides, faith.
Proto-Indo-European
*bʰeydʰ-
Latin
īnfidēlitās
Middle French
infidelité
Middle English
infidelite
English, today
infidelity
From Middle English infidelite, from Middle French infidelité (modern French infidélité) and its etymon Latin īnfidēlitās. Equivalent to infidel + ity.
Etymology from Wiktionary, CC BY-SA