perturbation (n.)youdaoicibaDictYouDict[perturbation 词源字典]
late 14c., from Old French perturbacion "disturbance, confusion" (14c.) and directly from Latin perturbationem (nominative perturbatio) "confusion, disorder, disturbance," noun of action from past participle stem of perturbare (see perturb).[perturbation etymology, perturbation origin, 英语词源]