fiftieth (adj.)youdaoicibaDictYouDict[fiftieth 词源字典]
Old English fifteogoða "fiftieth;" see fifty + -th (1). Compare Old Norse fimmtugande, and, with a different suffix, Old Frisian fiftichsta, Dutch vijftigste, Old High German fimfzugsto, German fünfzigste.[fiftieth etymology, fiftieth origin, 英语词源]