15-Letter Words Matching ____A_______R__

There are 13 15-letter words that match ____A_______R__. 1 are common words, such as INFRASTRUCTURES and INFRASTRUCTURAL. A rarer one is ULTRASTRUCTURES. In this set, R is the most frequent open letter (13 words). 2 words contain a doubled letter.

Full list 13

infrastructuresinfrastructuralintramuscularlycontainerboardsextracellularlyintracellularlyintravascularlypremanufacturedpremanufacturessporangiophorestetrahydrofuranultrastructuralultrastructures

About this list

Words
13 (1 common words)
Common example
infrastructures
Rare example
ultrastructures
Doubled letters
2
Ending in S
5
Most frequent letter
R (13)

Questions

How many 15-letter words matching ____a_______r__ are there?

13. 1 of them are common words.

What is a common example?

INFRASTRUCTURES is among the common words in this set.