There are 8 13-letter words that start with 'fla'.
| flabbergasted | flagellantism | 
| flagellations | flamboyancies | 
| flameproofers | flameproofing | 
| flamethrowers | flavoproteins | 
Note: These 8 13-letter words that start with 'fla' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with flat, flag, flam, flas, flav, flan, flap, flab, flau, flak, flac, flaw, flar, flax, flai, flay.
4-letter words start with 'fla' (10)