Meaning of FIDELITY in English
[noun] [U] [formal] - honest or lasting support; loyaltyThey had shown great fidelity to Brighton, spending their holidays there for twenty years.(figurative) Her paintings show her remarkable fidelity to detail (= the careful attention that she gives to detail).The play was Somerset Maugham's 1920s comedy of marital fidelity, 'The Constant Wife'.How important do you think sexual fidelity (= having a sexual relationship only with your partner) is in a marriage?
Cambridge English vocab. Кембриджский английский словарь. 2012