plenary (adj.)youdaoicibaDictYouDict[plenary 词源字典]
1510s, earlier plenar (mid-13c.), from Old French plenier, from Medieval Latin plenarius "entire, complete," from Latin plenus "full, filled, greatly crowded; stout, pregnant; abundant, abounding; complete," from PIE *pele- (1) "to fill" (see poly-). Related: Plenarily.[plenary etymology, plenary origin, 英语词源]