There are 17 words that start with 'forti'.
| fortis | forties |
| fortify | fortieth |
| fortieths | fortified |
| fortifier | fortifies |
| fortitude | fortifiers |
| fortifying | fortissimi |
| fortissimo | fortitudes |
| fortissimos | fortification |
| fortifications | |
Note: These 17 words that start with 'forti' are found from the USA & Canada version of the tournament Scrabble word list.