There are 5 15-letter words that start with 'disp'.
| disparatenesses | dispassionately | 
| disposabilities | disproportional | 
| disproportioned | |
Note: These 5 15-letter words that start with 'disp' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with dispe, displ, dispo, dispr, dispa, dispu, dispi.
6-letter words start with 'disp' (1)