15-Letter Words Matching ____O_____O____

There are 33 15-letter words that match ____O_____O____. 2 are common words, such as DISCONTINUOUSLY and PRECONDITIONING. A rarer one is UNPROFESSIONALS. In this set, I is the most frequent open letter (29 words). 2 words contain a doubled letter.

Full list 33

Common words

discontinuouslypreconditioningadenoidectomiesethnomusicologygeomorphologiesimprovisatorialmastoidectomiesneurophysiologynitrochloroformoligonucleotidepaleopsychologyunproportionate
discontinuouslypreconditioningadenoidectomiesethnomusicologygeomorphologiesimprovisatorialmastoidectomiesneurophysiologynitrochloroformoligonucleotidepaleopsychologyunproportionatechemotaxonomieschemotaxonomistepizootiologiesgeomorphologisthistophysiologymicrogametocytemicromorphologyneuroblastomataneuropsychologynoncontemporaryoligodendrocyteoligodendrogliapathophysiologyphenomenologiesphenomenologistphonocardiogrampreformationistretroperitonealsigmoidoscopiesthyroidectomiesunprofessionals

About this list

Words
33 (2 common words)
Common example
discontinuously
Rare example
unprofessionals
Doubled letters
2
Ending in S
9
Most frequent letter
I (29)

Questions

How many 15-letter words matching ____o_____o____ are there?

33. 2 of them are common words.

What is a common example?

DISCONTINUOUSLY is among the common words in this set.