13-Letter Words Matching _A__________T

There are 20 13-letter words that match _A__________T. 5 are common words, such as CALLIGRAPHIST and CAMPANOLOGIST. A rarer one is SACERDOTALIST. In this set, I is the most frequent open letter (17 words). 4 words contain a doubled letter.

Full list 20

calligraphistcampanologistmaladjustmentrapprochementsadomasochistbamboozlementcalorifacientcatastrophistmariculturistwatercoloristcaulifloweretgastroscopistlaparoscopistmacronutrientmalariologistmartyrologistnarratologistpaleobotanistparticularistsacerdotalist

About this list

Words
20 (5 common words)
Common example
calligraphist
Rare example
sacerdotalist
Doubled letters
4
Ending in S
0
Most frequent letter
I (17)

Questions

How many 13-letter words matching _a__________t are there?

20. 5 of them are common words.

What is a common example?

CALLIGRAPHIST is among the common words in this set.