7-Letter Words Matching H_____M

There are 13 7-letter words that match H_____M. 7 are common words, such as HAFNIUM and HAHNIUM. A rarer one is HOBOISM. In this set, I is the most frequent open letter (10 words). 2 words contain a doubled letter.

Full list 13

hafniumhahniumheroismholmiumhomonymhoodlumhumdrumhalidomhassiumheirdomhadarimhazanimhoboism

About this list

Words
13 (7 common words)
Common example
hafnium
Rare example
hoboism
Doubled letters
2
Ending in S
0
Most frequent letter
I (10)

Questions

How many 7-letter words matching h_____m are there?

13. 7 of them are common words.

What is a common example?

HAFNIUM is among the common words in this set.