13-Letter Words Matching _____I_____R_

There are 21 13-letter words that match _____I_____R_. 7 are common words, such as COMPLIMENTARY and CONQUISTADORS. A rarer one is SEMIDIAMETERS. In this set, T is the most frequent open letter (20 words). 3 words contain a doubled letter.

Full list 21

complimentaryconquistadorsdehumidifiersexpeditionaryexperimenterspractitionersquestionnairearboricultureexhibitionersscintillatorsstirpiculturetransitionaryantibillboardcontainerportequilibratorsequilibratoryfractionatorshypopituitaryinterindustrymaterializerssemidiameters

About this list

Words
21 (7 common words)
Common example
complimentary
Rare example
semidiameters
Doubled letters
3
Ending in S
10
Most frequent letter
T (20)

Questions

How many 13-letter words matching _____i_____r_ are there?

21. 7 of them are common words.

What is a common example?

COMPLIMENTARY is among the common words in this set.