15-Letter Words Matching ____E________O_

There are 13 15-letter words that match ____E________O_. 3 are common words, such as DIFFERENTIATION and PREREGISTRATION. A rarer one is SEPTENDECILLION. In this set, I is the most frequent open letter (13 words). 3 words contain a doubled letter.

Full list 13

differentiationpreregistrationsystematizationcholecalciferolproselytizationcatheterizationconveyorizationmathematizationmisrecollectionmisregistrationoverelaborationoverexpectationseptendecillion

About this list

Words
13 (3 common words)
Common example
differentiation
Rare example
septendecillion
Doubled letters
3
Ending in S
0
Most frequent letter
I (13)

Questions

How many 15-letter words matching ____e________o_ are there?

13. 3 of them are common words.

What is a common example?

DIFFERENTIATION is among the common words in this set.