There are 15 words that start with 'dull'.
| dull | dulls | dully |
| dulled | duller | dullard |
| dullest | dulling | dullish |
| dullards | dullness | dullishly |
| dullnesses | dullsville | dullsvilles |
Note: These 15 words that start with 'dull' are found from the USA & Canada version of the tournament Scrabble word list.