13-Letter Words Matching F_________O__

There are 20 13-letter words that match F_________O__. 9 are common words, such as FACILITATIONS and FELICITATIONS. A rarer one is FRACTIONATORS. In this set, S is the most frequent open letter (20 words). 5 words contain a doubled letter.

Full list 20

facilitationsfelicitationsfenestrationsfermentationsfibrillationsfinalizationsflagellationsfluoridationsfluorocarbonsforeconsciousfossiliferousfrumentaceousfeminizationsferrosiliconsfiberizationsflocculationsfluidizationsfluorinationsfocalizationsfractionators

About this list

Words
20 (9 common words)
Common example
facilitations
Rare example
fractionators
Doubled letters
5
Ending in S
20
Most frequent letter
S (20)

Questions

How many 13-letter words matching f_________o__ are there?

20. 9 of them are common words.

What is a common example?

FACILITATIONS is among the common words in this set.