10-Letter Words Matching _____T_F__

There are 21 10-letter words that match _____T_F__. 10 are common words, such as FLAGSTAFFS and FOODSTUFFS. A rarer one is RIJSTTAFEL. In this set, S is the most frequent open letter (17 words). 11 words contain a doubled letter.

Full list 21

flagstaffsfoodstuffspikestaffsplaintiffspocketsfulscientificunfaithfulungratefuluntruthfulwaitstaffscandytuftsdespitefulfeedstuffsoverstuffspinnatifiduntastefulbasketsfulbucketsfulcowlstaffsoverstaffsrijsttafel

About this list

Words
21 (10 common words)
Common example
flagstaffs
Rare example
rijsttafel
Doubled letters
11
Ending in S
10
Most frequent letter
S (17)

Questions

How many 10-letter words matching _____t_f__ are there?

21. 10 of them are common words.

What is a common example?

FLAGSTAFFS is among the common words in this set.