15-Letter Words Matching _____A_____T___

There are 20 15-letter words that match _____A_____T___. 8 are common words, such as CONFRATERNITIES and CRYSTALLIZATION. A rarer one is UNDERACTIVITIES. 6 words contain a doubled letter.

Full list 20

confraternitiescrystallizationhyperactivitiesprocrastinatingprocrastinationprocrastinatorsradioactivitiesstandardizationcontractilitiescontravallationmetamathematicsprocrastinatorycrystallinitiesdiffractometersdiffractometricnonquantitativepostvaccinationretroactivitiessuperactivitiesunderactivities

About this list

Words
20 (8 common words)
Common example
confraternities
Rare example
underactivities
Doubled letters
6
Ending in S
11

Questions

How many 15-letter words matching _____a_____t___ are there?

20. 8 of them are common words.

What is a common example?

CONFRATERNITIES is among the common words in this set.