15-Letter Words Matching __R__________T_

There are 19 15-letter words that match __R__________T_. 5 are common words, such as CARCINOGENICITY and HARPSICHORDISTS. A rarer one is TERRITORIALISTS. In this set, I is the most frequent open letter (19 words). 8 words contain a doubled letter.

Full list 19

carcinogenicityharpsichordistshorticulturistsmarriageabilitystraightjacketscircumstantiateirresistibilityirreversibilitymerchantabilitypyroelectricityaerodynamicistsarrondissementsdorsiventralitydorsoventralityirreformabilityirrefragabilityirrepealabilityparasitologiststerritorialists

About this list

Words
19 (5 common words)
Common example
carcinogenicity
Rare example
territorialists
Doubled letters
8
Ending in S
7
Most frequent letter
I (19)

Questions

How many 15-letter words matching __r__________t_ are there?

19. 5 of them are common words.

What is a common example?

CARCINOGENICITY is among the common words in this set.