11-Letter Words Matching ____H__O___

There are 23 11-letter words that match ____H__O___. 5 are common words, such as BIRTHSTONES and KNIGHTHOODS. A rarer one is TRIPHTHONGS. In this set, T is the most frequent open letter (17 words). 4 words contain a doubled letter.

Full list 23

birthstonesknighthoodstouchstonestrichinosestrichinosisantiheroineepiphytoticgoodhumoredgraphomotormorphologicpitchstonespsychomotorpyrrhuloxiasaccharosesscyphozoansstephanotistrichomonadtrophozoitebeachfrontsbrightworkspsychologictrichomonaltriphthongs

About this list

Words
23 (5 common words)
Common example
birthstones
Rare example
triphthongs
Doubled letters
4
Ending in S
12
Most frequent letter
T (17)

Questions

How many 11-letter words matching ____h__o___ are there?

23. 5 of them are common words.

What is a common example?

BIRTHSTONES is among the common words in this set.