Praetorian (adj.)youdaoicibaDictYouDict[Praetorian 词源字典]
early 15c., from Latin praetorianus "belonging to a praetor," from praetor (see praetor). Praetorian Guard is from cohors praetoria, the bodyguard troop of a Roman commander or emperor. Hence modern figurative use for "defenders of an existing order."[Praetorian etymology, Praetorian origin, 英语词源]