12-Letter Words Matching ___DR_______

There are 20 12-letter words that match ___DR_______. 9 are common words, such as QUADRANGULAR and QUADRAPHONIC. A rarer one is QUADRIPHONIC. In this set, I is the most frequent open letter (17 words). 6 words contain a doubled letter.

Full list 20

quadrangularquadraphonicquadrenniumsquadricepsesquadrillionsquadriplegiaquadriplegictawdrinessestopdressingsdendrologistquadrinomialquadrivalentquadrumanouswondrousnessdaydreamlikedendrologiesfundraisingshandrailingsquadrennialsquadriphonic

About this list

Words
20 (9 common words)
Common example
quadrangular
Rare example
quadriphonic
Doubled letters
6
Ending in S
11
Most frequent letter
I (17)

Questions

How many 12-letter words matching ___dr_______ are there?

20. 9 of them are common words.

What is a common example?

QUADRANGULAR is among the common words in this set.