practitioner (n.)youdaoicibaDictYouDict[practitioner 词源字典]
1540s, a hybrid formed from practitian "practitioner" (c. 1500, from French practicien, from Late Latin practicus "fit for action," see practice (v.)) on model of parishioner. Johnson has as a secondary sense "One who uses any sly or dangerous arts."[practitioner etymology, practitioner origin, 英语词源]