| 1 | English | Extension | — |
| 2 | Middle English | extensioun | — |
| 3 | Old French | estension | — |
| 4 | Latin | extensio | extension, stretching; swelling, tumour |
| 5 | Latin | -tiō | — |
| 6 | Latin | dissertātiō | — |
| 7 | Latin | dissertus | arranged, disposed; explained |
| 8 | Latin | disserere | second-person singular future passive indicative... |
| 9 | Latin | dis- | asunder, apart, in two; reversal, removal;... |
| 10 | Latin | calceus | shoe |
| 11 | Latin | calx | limestone; chalk; the finish line |
| 12 | Ancient Greek | χάλιξ | small stone, pebble; gravel, rubble |