14-Letter Words Matching ____RF________

There are 12 14-letter words that match ____RF________. 3 are common words, such as CHEERFULNESSES and COLORFULNESSES. A rarer one is INTERFERTILITY. In this set, E is the most frequent open letter (12 words). 3 words contain a doubled letter.

Full list 12

cheerfulnessescolorfulnessessuperficialityinterferometerinterferometrypowerfulnessessuperfetationshyperfunctionsinterfacultiesinterferentialinterferogramsinterfertility

About this list

Words
12 (3 common words)
Common example
cheerfulnesses
Rare example
interfertility
Doubled letters
3
Ending in S
7
Most frequent letter
E (12)

Questions

How many 14-letter words matching ____rf________ are there?

12. 3 of them are common words.

What is a common example?

CHEERFULNESSES is among the common words in this set.