There are 16 9-letter words that start with 'dou'.
| doubleton | doubloons | doublures | 
| doubtable | doubtless | douchebag | 
| doughboys | doughface | doughiest | 
| doughlike | doughnuts | doughtier | 
| doughtily | doupionis | douppioni | 
| douzepers | ||
Note: These 16 9-letter words that start with 'dou' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with doub, doug, dour, douc, dous, doum, doup, doul, douz, doux.
4-letter words start with 'dou' (3)