15-Letter Words Matching _I________R____

There are 20 15-letter words that match _I________R____. 5 are common words, such as DISCIPLINARIANS and DISEQUILIBRIUMS. A rarer one is VIDEOCONFERENCE. 2 words contain a doubled letter.

Full list 20

disciplinariansdisequilibriumsmicroelectronicmicrometeoritesnitroglycerinesbioengineeringsdistributorshippiezoelectricalpithecanthropusbiostratigraphycitriculturistsdisequilibrateddisequilibratesmicrobarographsmicroelectrodesmicrometeoriticmicrometeoroidssilviculturallysilviculturistsvideoconference

About this list

Words
20 (5 common words)
Common example
disciplinarians
Rare example
videoconference
Doubled letters
2
Ending in S
12

Questions

How many 15-letter words matching _i________r____ are there?

20. 5 of them are common words.

What is a common example?

DISCIPLINARIANS is among the common words in this set.