11-Letter Words Matching _N________M

There are 22 11-letter words that match _N________M. 3 are common words, such as ANACHRONISM and INCUNABULUM. A rarer one is INTERSYSTEM. In this set, I is the most frequent open letter (22 words). 3 words contain a doubled letter.

Full list 22

anachronismincunabuluminterregnumanamorphismantependiumantheridiumantifascismantirrhinumendocardiumendocraniumendometriumendotheciumendotheliuminfantilisminfusionisminsectariumintuitivismunnilhexiumanimalculumantielitismantirealismintersystem

About this list

Words
22 (3 common words)
Common example
anachronism
Rare example
intersystem
Doubled letters
3
Ending in S
0
Most frequent letter
I (22)

Questions

How many 11-letter words matching _n________m are there?

22. 3 of them are common words.

What is a common example?

ANACHRONISM is among the common words in this set.