à bord [OF]
abord [MI]
aboard [ME]
abôrd
https://www.etymonline.com/word/aboard#etymonline_v_55
https://quod.lib.umich.edu/m/middle-english-dictionary/dictionary/MED140
https://www.collinsdictionary.com/us/dictionary/french-english/aborder
https://www.collinsdictionary.com/us/dictionary/french-english/à-bord