There are 14 words that start with 'incap'.
| incapable | incapably | 
| incapacity | incapability | 
| incapacitate | incapacities | 
| incapableness | incapacitated | 
| incapacitates | incapabilities | 
| incapacitating | incapacitation | 
| incapablenesses | incapacitations | 
Note: These 14 words that start with 'incap' are found from the USA & Canada version of the tournament Scrabble word list.