15-Letter Words Matching ______Y_______S

There are 18 15-letter words that match ______Y_______S. 2 are common words, such as HYPOTHYROIDISMS and POLIOMYELITIDES. A rarer one is SUPERSYMMETRIES. In this set, O is the most frequent open letter (16 words). 2 words contain a doubled letter.

Full list 18

hypothyroidismspoliomyelitidescholecystitidesdimenhydrinatesosteomyelitideszygophyllaceousadenohypophysesadenohypophysisapocalypticismscholecystitiseshydroxyapatiteshydroxyprolinesmethoxyfluranesneurohypophysesneurohypophysisstrongyloidosesstrongyloidosissupersymmetries

About this list

Words
18 (2 common words)
Common example
hypothyroidisms
Rare example
supersymmetries
Doubled letters
2
Ending in S
18
Most frequent letter
O (16)

Questions

How many 15-letter words matching ______y_______s are there?

18. 2 of them are common words.

What is a common example?

HYPOTHYROIDISMS is among the common words in this set.