12-Letter Words Matching ___X_______S

There are 18 12-letter words that match ___X_______S. 3 are common words, such as ASEXUALITIES and COEXISTENCES. A rarer one is THIXOTROPIES. In this set, I is the most frequent open letter (17 words). 6 words contain a doubled letter.

Full list 18

asexualitiescoexistencesplexiglassesalexandritesamoxicillinsdeoxyribosesflexiblenessalexandrinesamoxycillinscloxacillinsdeoxidationsdeoxygenatesepoxidationsinexistencesinexpertnesspraxeologiesreoxidationsthixotropies

About this list

Words
18 (3 common words)
Common example
asexualities
Rare example
thixotropies
Doubled letters
6
Ending in S
18
Most frequent letter
I (17)

Questions

How many 12-letter words matching ___x_______s are there?

18. 3 of them are common words.

What is a common example?

ASEXUALITIES is among the common words in this set.