15-Letter Words Matching A_____T________

There are 23 15-letter words that match A_____T________. 3 are common words, such as AIRWORTHINESSES and APPRENTICESHIPS. A rarer one is AXIOMATIZATIONS. In this set, I is the most frequent open letter (21 words). 7 words contain a doubled letter.

Full list 23

airworthinessesapprenticeshipsauthenticationsaccountablenessalgorithmicallyantinationalistautolithographyaccountantshipsallotetraploidsallotetraploidyanfractuositiesantimaterialismantimaterialistantimetabolitesantirationalismantirationalistantirationalityautochthonouslyautomatizationsautotetraploidsautotetraploidyaxiomatisationsaxiomatizations

About this list

Words
23 (3 common words)
Common example
airworthinesses
Rare example
axiomatizations
Doubled letters
7
Ending in S
12
Most frequent letter
I (21)

Questions

How many 15-letter words matching a_____t________ are there?

23. 3 of them are common words.

What is a common example?

AIRWORTHINESSES is among the common words in this set.