There are 12 words that start with 'evap'.
| evaporate | evaporite | evaporated | 
| evaporates | evaporator | evaporites | 
| evaporitic | evaporating | evaporation | 
| evaporative | evaporators | evaporations | 
Note: These 12 words that start with 'evap' are found from the USA & Canada version of the tournament Scrabble word list.