There are 18 words that start with 'stiff'.
| stiff | stiffs | stiffed |
| stiffen | stiffer | stiffie |
| stiffly | stiffens | stiffest |
| stiffies | stiffing | stiffish |
| stiffened | stiffener | stiffness |
| stiffeners | stiffening | stiffnesses |
Note: These 18 words that start with 'stiff' are found from the USA & Canada version of the tournament Scrabble word list.