15-Letter Words Matching H_____________Y

There are 18 15-letter words that match H_____________Y. 3 are common words, such as HETEROGENEOUSLY and HETEROSEXUALITY. A rarer one is HYPNOTIZABILITY. In this set, L is the most frequent open letter (17 words). 11 words contain a doubled letter.

Full list 18

heterogeneouslyheterosexualityhypercriticallyheartbreakinglyheliocentricityhermeneuticallyholographicallyhomeopathicallyhorticulturallyhydrometallurgyhydrostaticallyheliometricallyhemodynamicallyhistochemicallyhistophysiologyhypermutabilityhyperreactivityhypnotizability

About this list

Words
18 (3 common words)
Common example
heterogeneously
Rare example
hypnotizability
Doubled letters
11
Ending in S
0
Most frequent letter
L (17)

Questions

How many 15-letter words matching h_____________y are there?

18. 3 of them are common words.

What is a common example?

HETEROGENEOUSLY is among the common words in this set.