| 1 | Middle English | blithe | — |
| 2 | Old English | blīþe | blithe, joyous, cheerful, pleasant; gracious,... |
| 3 | Proto-West Germanic | blīþī | happy |
| 4 | Proto-Germanic | blīþiz | serene, mild; pleasant, pleasing, delightful,... |
| 5 | Proto-Indo-European | bʰlī- | light, pleasant, fine; light, fine, pleasant |
| 6 | Proto-Indo-European | bʰleh₁- | to bleat; to cry; to blow |
| 7 | Proto-Indo-European | bʰel- | to sound; to speak, roar, bark; shiny, white; to... |
| 8 | Proto-Indo-European | bʰōl- | — |