| 1 | English | vigorous | Physically strong and active; Mentally strong and... |
| 2 | Old French | vigrus | strong; hardy |
| 3 | Old French | vigoros | — |
| 4 | Latin | vigorosus | — |
| 5 | Latin | vigor | vigor, liveliness, activity; power, strength |
| 6 | Latin | -or | used to form a third-declension masculine... |
| 7 | Proto-Italic | -ōs | Creates masculine action nouns or result nouns... |
| 8 | Proto-Indo-European | -ōs | Creates masculine and feminine action nouns or... |
| 9 | Proto-Indo-European | -oss | — |
| 10 | Proto-Indo-European | -os | Creates action nouns or result nouns from verbs;... |