15-Letter Words Matching ____OS_________

There are 35 15-letter words that match ____OS_________. 7 are common words, such as EXPLOSIVENESSES and INTROSPECTIVELY. A rarer one is SACROSANCTITIES. In this set, I is the most frequent open letter (31 words). 12 words contain a doubled letter.

Full list 35

Common words

explosivenessesintrospectivelymicroscopicallyphilosophicallyphotosynthesizeprepositionallyretrospectivelyhydrostaticallymacroscopicallymicrosporangiummicrosporophylloligosaccharide
explosivenessesintrospectivelymicroscopicallyphilosophicallyphotosynthesizeprepositionallyretrospectivelyhydrostaticallymacroscopicallymicrosporangiummicrosporophylloligosaccharidephotosensitizedphotosensitizespurposelessnesscompositionallycorrosivenessesdephosphorylatedisposabilitiesintrospectionallignosulfonatesmacrostructuralmacrostructuresmicroseismicitymicrosporocytesmicrostructuralmicrostructuresneuroscientificneuroscientistsneurosecretionsnonhospitalizedphotosensitizerpurposivenessesradiostrontiumssacrosanctities

About this list

Words
35 (7 common words)
Common example
explosivenesses
Rare example
sacrosanctities
Doubled letters
12
Ending in S
14
Most frequent letter
I (31)

Questions

How many 15-letter words matching ____os_________ are there?

35. 7 of them are common words.

What is a common example?

EXPLOSIVENESSES is among the common words in this set.