There are 11 words that start with 'sextu'.
| sextuple | sextuply | 
| sextupled | sextuples | 
| sextuplet | sextuplets | 
| sextupling | sextuplicate | 
| sextuplicated | sextuplicates | 
| sextuplicating | |
Note: These 11 words that start with 'sextu' are found from the USA & Canada version of the tournament Scrabble word list.