Thirtieth
来自Big Physics
Safin（讨论 | 贡献）2022年4月28日 (四) 23:53的版本 （建立内容为“Category:etymology == wiktionary == [https://en.wiktionary.org/wiki/thirtieth ref] From [https://en.wikipedia.org/wiki/Middle_English Middle English] thretti…”的新页面）
wiktionary
From Middle English threttiþe, thrittyde; equivalent to thirty + -eth.
etymonline
thirtieth (adj., n.)
"next in order after the twenty-ninth; an ordinal numeral; being one of thirty equal parts into which a whole is regarded as divided;" Middle English threttyth, from Old English þritigoða; see thirty + -th (1). Respelled 16c. to conform to new spelling of thirty.
