- fifteenth (adj.)
[fifteenth 词源字典]
- late 14c., from fifteen + -th (1). By 15c. displacing forms derived from Old English fifteoða. Compare Old Frisian fiftuda, Dutch vijftiende, German fünfzehnte, Old Norse fimmtandi, Gothic fimftataihunda, with ordinal -d where English has -th. As a noun by late 14c.[fifteenth etymology, fifteenth origin, 英语词源]