8-Letter Words Matching ___E_F__

There are 21 8-letter words that match ___E_F__. 5 are common words, such as CHEERFUL and POWERFUL. A rarer one is WAVEOFFS. In this set, R is the most frequent open letter (12 words). 11 words contain a doubled letter.

Full list 21

cheerfulpowerfultakeoffsunderfedunderfurfeverfewgreenflysuperfixalderflybedeafencheekfulenfeoffsenserfedhoneyfulinfeoffsrakeoffssheenfulsheetfedsneerfulsuperfanwaveoffs

About this list

Words
21 (5 common words)
Common example
cheerful
Rare example
waveoffs
Doubled letters
11
Ending in S
5
Most frequent letter
R (12)

Questions

How many 8-letter words matching ___e_f__ are there?

21. 5 of them are common words.

What is a common example?

CHEERFUL is among the common words in this set.