15-Letter Words Matching ___I______O____

There are 12 15-letter words that match ___I______O____. 3 are common words, such as ANTIABORTIONIST and NONINFLATIONARY. A rarer one is SEDIMENTOLOGIST. In this set, T is the most frequent open letter (11 words). 3 words contain a doubled letter.

Full list 12

antiabortionistnoninflationarypusillanimouslyassimilationistlepidopterologyanticarcinogensantiforeclosureassimilationismcleistogamouslydisinflationarysedimentologiessedimentologist

About this list

Words
12 (3 common words)
Common example
antiabortionist
Rare example
sedimentologist
Doubled letters
3
Ending in S
2
Most frequent letter
T (11)

Questions

How many 15-letter words matching ___i______o____ are there?

12. 3 of them are common words.

What is a common example?

ANTIABORTIONIST is among the common words in this set.