thirteenth (adj.)youdaoicibaDictYouDict[thirteenth 词源字典]
15c. metathesis of þriteenþe (mid-14c.; see thirteen + -th (1)), which replaced forms from Old English þreoteoða (West Saxon), þriteogeða (Anglian). Similar formation in Old Norse þrettande, Danish trettende, Swedish trettonde, Old Frisian threttinde, Dutch dertiende, Old High German dritto-zehanto, German dreizehnte.[thirteenth etymology, thirteenth origin, 英语词源]