15-Letter Words Matching ____F_________S

There are 21 15-letter words that match ____F_________S. 5 are common words, such as ARTIFICIALITIES and DISAFFILIATIONS. A rarer one is VERIFIABILITIES. In this set, E is the most frequent open letter (20 words). 13 words contain a doubled letter.

Full list 21

artificialitiesdisaffiliationsineffectivenessinoffensivenessinsufficienciesdinoflagellatesineffectualnessantifederalistsantifilibustersbarefacednessescodifiabilitiesdecaffeinationsgyrofrequencieshemoflagellatesindefinablenessindifferentismsindifferentistsineffablenessesmetafictionistsmodifiabilitiesverifiabilities

About this list

Words
21 (5 common words)
Common example
artificialities
Rare example
verifiabilities
Doubled letters
13
Ending in S
21
Most frequent letter
E (20)

Questions

How many 15-letter words matching ____f_________s are there?

21. 5 of them are common words.

What is a common example?

ARTIFICIALITIES is among the common words in this set.