| 1 | French | Judicaël | — |
| 2 | Old Breton | Iudicael | — |
| 3 | Welsh | cael | to get, receive, have; to get to, be allowed to,... |
| 4 | English | Kyle | — |
| 5 | Scottish Gaelic | caol | thin, narrow; strait, narrows, firth, kyle; the... |
| 6 | Middle Irish | cáel | narrow |
| 7 | Old Irish | coíl | — |
| 8 | Proto-Celtic | koilos | thin |
| 9 | Proto-Indo-European | sḱēy- | to shine; to shimmer; shadow; luster, gloss,... |
| 10 | Proto-Germanic | skaidą | separation, distinction |
| 11 | Proto-Indo-European | skÁit- | to cut, part, spearate, divide; to cut, part,... |