There are 10 7-letter words that start with 'eff'.
| effable | effaced | effacer | effaces | 
| effects | effendi | efforts | effulge | 
| effused | effuses | ||
Note: These 10 7-letter words that start with 'eff' are found from the USA & Canada version of the tournament Scrabble word list.
Also see words start with effe, effl, effu, effi, effa, effo, effr, effs.
4-letter words start with 'eff' (1)