stratification (n.)youdaoicibaDictYouDict[stratification 词源字典]
1610s, from Medieval Latin stratificationem (nominative stratificatio), noun of action from past participle stem of stratificare "to form strata," from stratum "thing spread out" (see stratum) + root of facere "to make" (see factitious). In sociology from 1879.[stratification etymology, stratification origin, 英语词源]