There are 13 words that start with 'lithi'.
| lithia | lithic | 
| lithias | lithify | 
| lithium | lithiums | 
| lithiases | lithiasis | 
| lithified | lithifies | 
| lithifying | lithification | 
| lithifications | |
Note: These 13 words that start with 'lithi' are found from the USA & Canada version of the tournament Scrabble word list.