| 1 | Middle English | twyll | — |
| 2 | Old English | twilic | two-threaded |
| 3 | Latin | bilix | having a double thread |
| 4 | Latin | bis | twice, two times, on two occasions, in two ways |
| 5 | Latin | color | colour, shade; color; pigment; complexion |
| 6 | Ancient Greek | μέτρον | something used to measure: measure, rule, weight;... |
| 7 | Ancient Greek | -τρον | Forms instrument nouns |
| 8 | Proto-Hellenic | -tron | Forms instrument nouns from verb stems |
| 9 | Proto-Indo-European | -trom | Forms nouns denoting a tool or instrument |
| 10 | Proto-Indo-European | -tḗr | Derives agent nouns from verbs, denoting someone... |