14-Letter Words Matching ____O_____R___

There are 31 14-letter words that match ____O_____R___. 9 are common words, such as MICROBREWERIES and MICROMETEORITE. A rarer one is RADIOAUTOGRAPH. In this set, I is the most frequent open letter (27 words). 2 words contain a doubled letter.

Full list 31

Common words

microbreweriesmicrometeoritemicrosurgeriesneurosurgeriesnitroglycerinenitroglycerinsradiotelegraphschoolmistresstrigonometriesmicrobarographnitrobacteriumphotoelectrons
microbreweriesmicrometeoritemicrosurgeriesneurosurgeriesnitroglycerinenitroglycerinsradiotelegraphschoolmistresstrigonometriesmicrobarographnitrobacteriumphotoelectronsphototelegraphprotohistoriesuniformitarianaminoaciduriaschemosurgeriescyanobacteriumdiamondiferousethnohistorianethnohistoriesferroelectricsintroductorilymethoxyfluranemicroelectrodemicrometeoroidneuroendocrinephotoautotrophphycoerythrinsprotohistorianradioautograph

About this list

Words
31 (9 common words)
Common example
microbreweries
Rare example
radioautograph
Doubled letters
2
Ending in S
14
Most frequent letter
I (27)

Questions

How many 14-letter words matching ____o_____r___ are there?

31. 9 of them are common words.

What is a common example?

MICROBREWERIES is among the common words in this set.