9-Letter Words Matching R_____F__

There are 14 9-letter words that match R_____F__. 5 are common words, such as REGRETFUL and REPOSEFUL. A rarer one is RIFFRAFFS. In this set, E is the most frequent open letter (12 words). 6 words contain a doubled letter.

Full list 14

regretfulreposefulresentfulreshufflerestaffedreproofedrauwolfiaredshiftsregardfulremindfulrechaufferestuffedresultfulriffraffs

About this list

Words
14 (5 common words)
Common example
regretful
Rare example
riffraffs
Doubled letters
6
Ending in S
2
Most frequent letter
E (12)

Questions

How many 9-letter words matching r_____f__ are there?

14. 5 of them are common words.

What is a common example?

REGRETFUL is among the common words in this set.