14-Letter Words Matching __________H_N_

There are 21 14-letter words that match __________H_N_. 7 are common words, such as ACETAMINOPHENS and BACKSCRATCHING. A rarer one is ULTRAMARATHONS. In this set, I is the most frequent open letter (20 words). 2 words contain a doubled letter.

Full list 21

acetaminophensbackscratchingchoreographingdistinguishingphotofinishingradiotelephonereestablishingoverstretchingradiotelephonytriiodomethanecanthaxanthinsdichloroethaneelectrofishinggonadotrophinsmethylxanthineovernourishingsilversmithingsomatotrophinsstereographingtrihalomethaneultramarathons

About this list

Words
21 (7 common words)
Common example
acetaminophens
Rare example
ultramarathons
Doubled letters
2
Ending in S
5
Most frequent letter
I (20)

Questions

How many 14-letter words matching __________h_n_ are there?

21. 7 of them are common words.

What is a common example?

ACETAMINOPHENS is among the common words in this set.