15-Letter Words Matching _______E__R____

There are 12 15-letter words that match _______E__R____. 2 are common words, such as MICROELECTRONIC and SEPTUAGENARIANS. A rarer one is SUBPROLETARIATS. In this set, I is the most frequent open letter (12 words). 1 words contain a doubled letter.

Full list 12

microelectronicseptuagenariansnorepinephrinesphotoelectricalpiezoelectricalamphitheatricalinterelectrodesinterelectronicmicroelectrodesphotoelectronicpremillenarianssubproletariats

About this list

Words
12 (2 common words)
Common example
microelectronic
Rare example
subproletariats
Doubled letters
1
Ending in S
6
Most frequent letter
I (12)

Questions

How many 15-letter words matching _______e__r____ are there?

12. 2 of them are common words.

What is a common example?

MICROELECTRONIC is among the common words in this set.