15-Letter Words Matching __T___________T

There are 12 15-letter words that match __T___________T. 2 are common words, such as ANTIABORTIONIST and INTERVENTIONIST. A rarer one is ULTRACONVENIENT. In this set, I is the most frequent open letter (12 words). 2 words contain a doubled letter.

Full list 12

antiabortionistinterventionistantinationalistmetempsychosistanticlericalistanticolonialistantidevelopmentantiferromagnetantimaterialistantirationalistintellectualistultraconvenient

About this list

Words
12 (2 common words)
Common example
antiabortionist
Rare example
ultraconvenient
Doubled letters
2
Ending in S
0
Most frequent letter
I (12)

Questions

How many 15-letter words matching __t___________t are there?

12. 2 of them are common words.

What is a common example?

ANTIABORTIONIST is among the common words in this set.