12-Letter Words Matching ____E____R__

There are 14 12-letter words that match ____E____R__. 4 are common words, such as CENTERBOARDS and FINGERBOARDS. A rarer one is TRIMETHOPRIM. In this set, O is the most frequent open letter (13 words). 1 words contain a doubled letter.

Full list 14

centerboardsfingerboardsmotherboardstemperaturespyroelectricteeterboardsantielectronbeaverboardsdipterocarpsgrotesquerienonmetamericoutdeliveredoverenamoredtrimethoprim

About this list

Words
14 (4 common words)
Common example
centerboards
Rare example
trimethoprim
Doubled letters
1
Ending in S
7
Most frequent letter
O (13)

Questions

How many 12-letter words matching ____e____r__ are there?

14. 4 of them are common words.

What is a common example?

CENTERBOARDS is among the common words in this set.