loyalty (n.)youdaoicibaDictYouDict[loyalty 词源字典]
c. 1400, from Old French loialté, leauté "loyalty, fidelity; legitimacy; honesty; good quality" (Modern French loyauté), from loial (see loyal). Earlier leaute (mid-13c.), from the older French form. Loyalty oath first attested 1852.[loyalty etymology, loyalty origin, 英语词源]