13-Letter Words Matching _I__________R

There are 12 13-letter words that match _I__________R. 4 are common words, such as BIBLIOGRAPHER and DISCRIMINATOR. A rarer one is MICROVASCULAR. In this set, R is the most frequent open letter (12 words). 2 words contain a doubled letter.

Full list 12

bibliographerdiscriminatorkindergartnermicrocomputerbiogeographercircumscriberdisintegratorfibrovascularmiddlebreakersinistrocularcircumstellarmicrovascular

About this list

Words
12 (4 common words)
Common example
bibliographer
Rare example
microvascular
Doubled letters
2
Ending in S
0
Most frequent letter
R (12)

Questions

How many 13-letter words matching _i__________r are there?

12. 4 of them are common words.

What is a common example?

BIBLIOGRAPHER is among the common words in this set.