12-Letter Words Matching H_____S_____

There are 18 12-letter words that match H_____S_____. 9 are common words, such as HAPPENSTANCE and HARMLESSNESS. A rarer one is HYPEROSTOTIC. In this set, E is the most frequent open letter (15 words). 11 words contain a doubled letter.

Full list 18

happenstanceharmlessnessheadmistresshearthstonesheedlessnesshelplessnessheterosexualhomelessnesshopelessnesshyperostosishypogastriumhairlessnesshandfastingsheadlessnesshornlessnesshypabyssallyhyperostoseshyperostotic

About this list

Words
18 (9 common words)
Common example
happenstance
Rare example
hyperostotic
Doubled letters
11
Ending in S
13
Most frequent letter
E (15)

Questions

How many 12-letter words matching h_____s_____ are there?

18. 9 of them are common words.

What is a common example?

HAPPENSTANCE is among the common words in this set.