13-Letter Words Matching ________RR___

There are 12 13-letter words that match ________RR___. 3 are common words, such as BOYSENBERRIES and CHOKECHERRIES. A rarer one is WINTERBERRIES. 12 words contain a doubled letter.

Full list 12

boysenberrieschokecherrieshuckleberriescandleberrieslingonberriesnonconcurrentsalmonberriesfarkleberriesnonconcurringsilverberrieswinterberriesdingleberries

About this list

Words
12 (3 common words)
Common example
boysenberries
Rare example
winterberries
Doubled letters
12
Ending in S
10

Questions

How many 13-letter words matching ________rr___ are there?

12. 3 of them are common words.

What is a common example?

BOYSENBERRIES is among the common words in this set.