| 1 | English | Billy | — |
| 2 | English | Bill | — |
| 3 | Middle English | bill | — |
| 4 | Old English | bil | a kind of sword or other bladed weapon,... |
| 5 | Frankish | billi | — |
| 6 | Proto-Germanic | bilją | a cutting implement; blade; axe; sword; spike;... |
| 7 | Proto-Germanic | harjaz | army; army leader; commander; warrior |
| 8 | Proto-Indo-European | kóryos | war; troops; army; war, troops |
| 9 | Proto-Indo-European | ḱer- | to grow, to make grow, to nourish; to plait,... |
| 10 | Proto-Indo-European | kr̥- | to turn, to bend |
| 11 | Proto-Indo-European | ker- | army |