15-Letter Words Matching ____S____I_____

There are 16 15-letter words that match ____S____I_____. 5 are common words, such as ATMOSPHERICALLY and DISESTABLISHING. A rarer one is TENOSYNOVITISES. In this set, I is the most frequent open letter (15 words). 7 words contain a doubled letter.

Full list 16

atmosphericallydisestablishingoversimplifyingtransmogrifyingverisimilitudesperistalticallytransvestitismsantishopliftingfetishisticallyhexosaminidasesindisciplinableionosphericallykinestheticallymagistraticallypreestablishingtenosynovitises

About this list

Words
16 (5 common words)
Common example
atmospherically
Rare example
tenosynovitises
Doubled letters
7
Ending in S
4
Most frequent letter
I (15)

Questions

How many 15-letter words matching ____s____i_____ are there?

16. 5 of them are common words.

What is a common example?

ATMOSPHERICALLY is among the common words in this set.