15-Letter Words Matching ____M____R_____

There are 12 15-letter words that match ____M____R_____. 4 are common words, such as CINEMATOGRAPHER and CINEMATOGRAPHIC. A rarer one is RUDIMENTARINESS. 3 words contain a doubled letter.

Full list 12

cinematographercinematographicundemonstrativeunfamiliaritieschromatographicextemporarinesschromatographedchromatographerfragmentarinessheadmastershipspostmastershipsrudimentariness

About this list

Words
12 (4 common words)
Common example
cinematographer
Rare example
rudimentariness
Doubled letters
3
Ending in S
6

Questions

How many 15-letter words matching ____m____r_____ are there?

12. 4 of them are common words.

What is a common example?

CINEMATOGRAPHER is among the common words in this set.