infidelity
noun /ˌɪnfɪˈdeləti/
/ˌɪnfɪˈdeləti/
[uncountable, countable] (plural infidelities)
- the act of not being faithful to your wife, husband or partner, by having sex with somebody else synonym unfaithfulness
- marital infidelity
- She could not forgive his infidelities.
- her infidelity to her husband
- His reputation has been damaged by allegations of marital infidelity.
Word Originlate Middle English (in the senses ‘lack of faith’ and ‘disloyalty’): from Old French infidelite or Latin infidelitas, from infidelis ‘not faithful’, from in- ‘not’ + fidelis ‘faithful’ (from fides ‘faith’, related to fidere ‘to trust’).