There are 15 words that start with 'leav'.
| leave | leavy | leaved | 
| leaven | leaver | leaves | 
| leavens | leavers | leavier | 
| leaving | leavened | leaviest | 
| leavings | leavening | leavenings | 
Note: These 15 words that start with 'leav' are found from the USA & Canada version of the tournament Scrabble word list.