| 1 | Middle English | boy | — |
| 2 | Middle Dutch | boeye | life buoy; float, buoy; shackle, fetter |
| 3 | Old French | boie | bond, chain; fetter, chain, clog |
| 4 | Latin | boia | fetter, collar for the neck |
| 5 | Ancient Greek | βοείη | ox hide |
| 6 | Ancient Greek | βοῦς | cow, ox, cattle; shield: ὃτι ἐκ βοείων ἐστι... |
| 7 | Latin | corvus | A raven; a bird associated with prophecy and... |
| 8 | Proto-Italic | korwos | — |
| 9 | Proto-Indo-European | ḱorh₂wós | — |
| 10 | Proto-Indo-European | ḱer- | to grow, to make grow, to nourish; to plait,... |
| 11 | Proto-Indo-European | kr̥- | to turn, to bend |
| 12 | Proto-Indo-European | ker- | army |