There are 16 words that start with 'flatl'.
| flatly | flatlet | flatland | 
| flatlets | flatline | flatling | 
| flatlong | flatlands | flatlined | 
| flatliner | flatlines | flatlings | 
| flatlander | flatliners | flatlining | 
| flatlanders | ||
Note: These 16 words that start with 'flatl' are found from the USA & Canada version of the tournament Scrabble word list.