9-Letter Words Matching ____HR___

There are 31 9-letter words that match ____HR___. 7 are common words, such as BIRTHRATE and CUTTHROAT. A rarer one is SOUTHRONS. In this set, O is the most frequent open letter (20 words). 7 words contain a doubled letter.

Full list 31

Common words

birthratecutthroatdiaphragmlunchroompreshrankpreshrinkpreshrunkbirthrootclathrateepiphragmerythrismerythrite
birthratecutthroatdiaphragmlunchroompreshrankpreshrinkpreshrunkbirthrootclathrateepiphragmerythrismerythritemisthrownsubshrubssynchronyurochromecalthropsdiachronyearthriseerythroiderythronsisochroneisochronsmisthrowsnonshrinkoutthrobsoutthrownoutthrowsoutthrustshophrothsouthrons

About this list

Words
31 (7 common words)
Common example
birthrate
Rare example
southrons
Doubled letters
7
Ending in S
8
Most frequent letter
O (20)

Questions

How many 9-letter words matching ____hr___ are there?

31. 7 of them are common words.

What is a common example?

BIRTHRATE is among the common words in this set.