There are 14 words that start with 'mastic'.
| mastic | mastics | 
| mastiche | masticate | 
| mastiches | masticated | 
| masticates | masticator | 
| masticating | mastication | 
| masticators | masticatory | 
| mastications | masticatories | 
Note: These 14 words that start with 'mastic' are found from the USA & Canada version of the tournament Scrabble word list.