15-Letter Words Matching _________S_O___

There are 13 15-letter words that match _________S_O___. 2 are common words, such as NONPROFESSIONAL and SUBPROFESSIONAL. A rarer one is SPINTHARISCOPES. 7 words contain a doubled letter.

Full list 13

nonprofessionalsubprofessionalnoncommissionedophthalmoscopespreprofessionalupperclasswomanupperclasswomencounterresponseinterdivisionalmultidivisionalophthalmoscopicretinoblastomasspinthariscopes

About this list

Words
13 (2 common words)
Common example
nonprofessional
Rare example
spinthariscopes
Doubled letters
7
Ending in S
3

Questions

How many 15-letter words matching _________s_o___ are there?

13. 2 of them are common words.

What is a common example?

NONPROFESSIONAL is among the common words in this set.