honest or lasting support, or loyalty, especially to a sexual partner

Somerset Maugham's comedy of marital fidelity, "The Constant Wife" 萨默塞特‧毛姆关于婚姻忠诚的喜剧《忠实的妻子》

How important do you think sexual fidelity is in a marriage? 你认为婚姻中肉体上的忠诚有多重要？

the degree to which the detail and quality of an original, such as a picture, sound, or story, is copied exactly

The best ink-jet printers can reproduce photographs with amazing fidelity. 最好的喷墨打印机输出的照片效果会非常逼真。