12-Letter Words Matching _S_________Y

There are 17 12-letter words that match _S_________Y. 4 are common words, such as ASTOUNDINGLY and ASTRINGENTLY. A rarer one is USUFRUCTUARY. In this set, T is the most frequent open letter (16 words). 10 words contain a doubled letter.

Full list 17

astoundinglyastringentlyesotericallyestheticallyassimilatoryastrobiologyastrogeologyessentialityisothermallyisotopicallypseudonymityassaultivelyassumabilityisochronallyisotonicallypsychrometryusufructuary

About this list

Words
17 (4 common words)
Common example
astoundingly
Rare example
usufructuary
Doubled letters
10
Ending in S
0
Most frequent letter
T (16)

Questions

How many 12-letter words matching _s_________y are there?

17. 4 of them are common words.

What is a common example?

ASTOUNDINGLY is among the common words in this set.