| 1 | Middle English | febly | Sadly, sorrowfully; in an upset or unhappy way;... |
| 2 | Middle English | feble | Feeble, weak, or strengthless; Insidious,... |
| 3 | Anglo-Norman | feble | weak, feeble; weak; feeble |
| 4 | Vulgar Latin | febelis | — |
| 5 | Latin | flēbilis | — |
| 6 | Latin | fleō | — |
| 7 | Proto-Italic | flēō | weep, cry |
| 8 | Proto-Indo-European | bʰléh₁- | — |
| 9 | Proto-Indo-European | bʰel- | to sound; to speak, roar, bark; shiny, white; to... |
| 10 | Proto-Indo-European | bʰōl- | — |