Mammoth Uncensored Word List:
18 words that are 17 letters long beginning with f in the mammoth uncensored word list.

fantasticalnesses fashionablenesses feebleheartedness ferrimagnetically fibromyomectomies fibromyxosarcomas fickleheartedness fictionalisations fictionalizations fierceheartedness fissiparousnesses flirtatiousnesses floriferousnesses foresightednesses fractionalisation fractionalization fractoluminescent fragmentarinesses