seofonteoþa [OE]
sevententhe [MI]
seventeenth [ME]
seventínþ
https://www.etymonline.com/word/seventeenth#etymonline_v_48733
https://www.merriam-webster.com/dictionary/seventeenth
https://quod.lib.umich.edu/m/middle-english-dictionary/dictionary/MED39690
https://bosworthtoller.com/27462