7-Letter Words Matching T___F__

There are 20 7-letter words that match T___F__. 10 are common words, such as TACTFUL and TANKFUL. A rarer one is TUBIFEX. In this set, R is the most frequent open letter (11 words). 8 words contain a doubled letter.

Full list 20

tactfultankfultariffstearfulthriftsthriftytraffictruffletunefultwelfthterefahtoilfultriffidtailfanteenfultipoffstrayfultroffertruffestubifex

About this list

Words
20 (10 common words)
Common example
tactful
Rare example
tubifex
Doubled letters
8
Ending in S
4
Most frequent letter
R (11)

Questions

How many 7-letter words matching t___f__ are there?

20. 10 of them are common words.

What is a common example?

TACTFUL is among the common words in this set.