14-Letter Words Matching _R_________A__

There are 12 14-letter words that match _R_________A__. 3 are common words, such as ARITHMETICIANS and TRANSNATIONALS. A rarer one is TRIHALOMETHANE. In this set, T is the most frequent open letter (12 words). 3 words contain a doubled letter.

Full list 12

arithmeticianstransnationalstricentennialscrosspollinateornithischianspredeterminateprestidigitatetriiodomethanecryoprotectantorthophosphateprotoplanetarytrihalomethane

About this list

Words
12 (3 common words)
Common example
arithmeticians
Rare example
trihalomethane
Doubled letters
3
Ending in S
4
Most frequent letter
T (12)

Questions

How many 14-letter words matching _r_________a__ are there?

12. 3 of them are common words.

What is a common example?

ARITHMETICIANS is among the common words in this set.