plenipotentiary (adj.)youdaoicibaDictYouDict[plenipotentiary 词源字典]
1640s, from French plénipotentiaire and directly from Medieval Latin plenipotentiarius "having full power," from Late Latin plenipotens, from Latin plenus "full" (see plenary) + potentem "powerful" (see potent). As a noun from 1650s.[plenipotentiary etymology, plenipotentiary origin, 英语词源]