mastery (n.)youdaoicibaDictYouDict[mastery 词源字典]
early 13c., mesterie, "condition of being a master," also "superiority, victory;" from Old French maistrie, from maistre "master" (see master (n.)). Meaning "intellectual command" (of a topic, etc.) is from 1660s.[mastery etymology, mastery origin, 英语词源]