one thousandth [ME]
oun þaosanþ
https://www.etymonline.com/word/thousandth#etymonline_v_48736
https://www.merriam-webster.com/dictionary/thousandth

millionth [ME]
milhonþ
https://www.etymonline.com/word/millionth#etymonline_v_44713
https://www.merriam-webster.com/dictionary/millionth

billionth [ME]
bilhonþ
https://www.etymonline.com/word/billionth#etymonline_v_43050
https://www.merriam-webster.com/dictionary/billionth

trillionth [ME]
trilhonþ
https://www.etymonline.com/word/trillionth#etymonline_v_49629
https://www.merriam-webster.com/dictionary/trillionth