There are 11 words that start with 'downst'.
| downstage | downstair | downstate | 
| downstages | downstairs | downstater | 
| downstates | downstream | downstroke | 
| downstaters | downstrokes | |
Note: These 11 words that start with 'downst' are found from the USA & Canada version of the tournament Scrabble word list.