What word in the English language has the most "f"'s in it?

I found riffraff with four f's.

http://dictionary.reference.com/browse/riffraff?s=t

there is also a variation of piff: piff-poff

https://www.lexico.com/definition/piff

There's a bird called the chiffchaff.

http://www.bto.org/about-birds/bird-id/willow-warbler-chiffchaff

I looked for words with 5 or more Fs using the site below, and found a lot of words with four of them, but most of the links led to a thesaurus entry with no definition. It did not give any results with five Fs. Of course, that just means that the person who compiled the database being searched didn't enter any such words, not that they don't exist.

(I am unable to post with the full link - if you follow this, you can enter the search details, starting with an asterisk, then alternating f and asterisk until you have the desired number of them, ending with an asterisk.)

http://itools.subhashbose.com/wordfind/pattern