15-Letter Words Matching A_____________T

There are 12 15-letter words that match A_____________T. 3 are common words, such as ACKNOWLEDGEMENT and AGRICULTURALIST. A rarer one is ANTIRATIONALIST. 2 words contain a doubled letter.

Full list 12

acknowledgementagriculturalistantiabortionistantinationalistarboriculturistassimilationistanticlericalistanticolonialistantidevelopmentantiferromagnetantimaterialistantirationalist

About this list

Words
12 (3 common words)
Common example
acknowledgement
Rare example
antirationalist
Doubled letters
2
Ending in S
0

Questions

How many 15-letter words matching a_____________t are there?

12. 3 of them are common words.

What is a common example?

ACKNOWLEDGEMENT is among the common words in this set.