| 1 | English | fluent | That flows; flowing, liquid; Able to use a... |
| 2 | Latin | fluens | flowing, streaming, pouring; being soaked in;... |
| 3 | Latin | fluō | — |
| 4 | Proto-Indo-European | bʰléh₁- | — |
| 5 | Proto-Indo-European | bʰel- | to sound; to speak, roar, bark; shiny, white; to... |
| 6 | Proto-Indo-European | bʰōl- | — |