| 1 | English | tremble | To shake, quiver, or vibrate; To fear; to be... |
| 2 | Old French | trambler | to tremble |
| 3 | Vulgar Latin | tremulare | present active infinitive of tremulō |
| 4 | Latin | tremulus | shaking, quaking, quivering, trembling, tremulous |
| 5 | Latin | tremō | — |
| 6 | Proto-Italic | tremō | — |
| 7 | Proto-Indo-European | trem- | to tremble |
| 8 | Proto-Indo-European | ter- | tender, weak; young creature |
| 9 | Italian | termine | end, close; limit, term, date, time; term, word |
| 10 | Latin | terminus | a boundary, limit, end |
| 11 | Proto-Italic | termenos | — |
| 12 | Proto-Indo-European | térmn̥ | boundary, end |