There are 9 words that start with 'letha'.
| lethal | lethals | 
| lethally | lethargy | 
| lethality | lethargic | 
| lethargies | lethalities | 
| lethargically | |
Note: These 9 words that start with 'letha' are found from the USA & Canada version of the tournament Scrabble word list.