15-Letter Words Matching ___N___N_______

There are 12 15-letter words that match ___N___N_______. 2 are common words, such as MAINTAINABILITY and MOUNTAINEERINGS. A rarer one is ROENTGENOLOGIST. 2 words contain a doubled letter.

Full list 12

maintainabilitymountaineeringscoinstantaneousethnocentricitytranscendenciesmountainousnessphenomenalisticphenomenologiesphenomenologistroentgenographyroentgenologiesroentgenologist

About this list

Words
12 (2 common words)
Common example
maintainability
Rare example
roentgenologist
Doubled letters
2
Ending in S
6

Questions

How many 15-letter words matching ___n___n_______ are there?

12. 2 of them are common words.

What is a common example?

MAINTAINABILITY is among the common words in this set.