11-Letter Words Matching ____R__F___

There are 19 11-letter words that match ____R__F___. 8 are common words, such as AFTEREFFECT and DIVERSIFIED. A rarer one is SUPERINFECT. In this set, E is the most frequent open letter (18 words). 4 words contain a doubled letter.

Full list 19

aftereffectdiversifieddiversifieshundredfoldinterofficerefortifiedrefortifiesunfortifieddiversiformuncertifiedairproofingdecertifieddecertifiesdiversifieroverruffingrecertifiedrecertifiesseveralfoldsuperinfect

About this list

Words
19 (8 common words)
Common example
aftereffect
Rare example
superinfect
Doubled letters
4
Ending in S
4
Most frequent letter
E (18)

Questions

How many 11-letter words matching ____r__f___ are there?

19. 8 of them are common words.

What is a common example?

AFTEREFFECT is among the common words in this set.