There are 15 words that start with 'sweep'.
| sweep | sweeps | 
| sweepy | sweeper | 
| sweepers | sweepier | 
| sweeping | sweepback | 
| sweepiest | sweepings | 
| sweepbacks | sweepingly | 
| sweepstakes | sweepingness | 
| sweepingnesses | |
Note: These 15 words that start with 'sweep' are found from the USA & Canada version of the tournament Scrabble word list.