11-Letter Words Matching _________F_

There are 22 11-letter words that match _________F_. 8 are common words, such as CHILDPROOFS and CLOVERLEAFS. A rarer one is SHANDYGAFFS. In this set, S is the most frequent open letter (18 words). 14 words contain a doubled letter.

Full list 22

childproofscloverleafsflameproofsmisidentifypocketknifesoundproofsspendthriftwaterproofsbreadstuffsheterograftloosestrifemisclassifyneedlecraftovermagnifyoverspecifypriestcraftsubclassifybullmastiffchiffchaffsgreenstuffshippogriffsshandygaffs

About this list

Words
22 (8 common words)
Common example
childproofs
Rare example
shandygaffs
Doubled letters
14
Ending in S
10
Most frequent letter
S (18)

Questions

How many 11-letter words matching _________f_ are there?

22. 8 of them are common words.

What is a common example?

CHILDPROOFS is among the common words in this set.