twentigoða [OE]
twentithe [MI]
twentieth [ME]
tɯontieþ
https://www.etymonline.com/word/twentieth#etymonline_v_46774
https://www.merriam-webster.com/dictionary/twentieth
https://quod.lib.umich.edu/m/middle-english-dictionary/dictionary/MED47467
https://bosworthtoller.com/31208

twenty-first [ME]
tɯonty-fêst

twenty-second [ME]
tɯonty-second

etc