11-Letter Words Matching _____DR____

There are 15 11-letter words that match _____DR____. 4 are common words, such as CYLINDRICAL and HIPPODROMES. A rarer one is TETRADRACHM. In this set, I is the most frequent open letter (12 words). 3 words contain a doubled letter.

Full list 15

cylindricalhippodromespalindromesscrewdriverpalindromicachondritesbiquadraticcalendricaloxyhydrogenscoundrellyspoondriftsachondriticmethedrinesroughdryingtetradrachm

About this list

Words
15 (4 common words)
Common example
cylindrical
Rare example
tetradrachm
Doubled letters
3
Ending in S
5
Most frequent letter
I (12)

Questions

How many 11-letter words matching _____dr____ are there?

15. 4 of them are common words.

What is a common example?

CYLINDRICAL is among the common words in this set.