15-Letter Words Matching _I___O_________

There are 13 15-letter words that match _I___O_________. 2 are common words, such as BIBLIOGRAPHICAL and DISPROPORTIONAL. A rarer one is MISSIONIZATIONS. In this set, I is the most frequent open letter (11 words). 2 words contain a doubled letter.

Full list 13

bibliographicaldisproportionalbiogeochemistrymillionairessesbibliotherapiesbiogeochemicalsbiogeographicaldichlorobenzenedichloroethanesdisproportioneddithiocarbamatefictionizationsmissionizations

About this list

Words
13 (2 common words)
Common example
bibliographical
Rare example
missionizations
Doubled letters
2
Ending in S
6
Most frequent letter
I (11)

Questions

How many 15-letter words matching _i___o_________ are there?

13. 2 of them are common words.

What is a common example?

BIBLIOGRAPHICAL is among the common words in this set.