in·fi·del·i·ty /ˌɪnfəˈdeləti/ noun (plural infidelities) [countableC, uncountableU] UNFAITHFULwhen someone has sex with a person who is not their wife, husband, or partner 〔对丈夫、妻子或伴侣的〕不贞行为 marital infidelity 对婚姻的不忠诚
infidelity• a marriage destroyed by infidelity• Her husband never knew of her infidelity.• There had been rumours for a long time of Clinton's marital infidelity.