Mammoth Uncensored Word List:
41 words ending with ff, 7 letters long

backoff bailiff boiloff caitiff castoff cookoff destaff destuff distaff dustoff earmuff enfeoff engraff faceoff falloff fuckoff handoff infeoff jumpoff kickoff leadoff liftoff mastiff midriff playoff pontiff rebluff restaff restiff restuff selloff sendoff sheriff showoff shutoff spinoff stopoff takeoff turnoff unstuff welloff