| 1 | Scots | fou | full; well-fed, full of food or drink, sated,... |
| 2 | Middle English | fúl | — |
| 3 | Old English | full | full, filled, complete, entire; a beaker; a cup,... |
| 4 | Proto-West Germanic | full | full |
| 5 | Proto-Germanic | fullaz | full; the whole, the entire |
| 6 | Proto-Indo-European | pl̥h₁nós | full |
| 7 | Proto-Indo-European | pleh₁- | to fill |