15-Letter Words Matching ___I___O_______

There are 20 15-letter words that match ___I___O_______. 3 are common words, such as PLAINCLOTHESMAN and PLAINCLOTHESMEN. A rarer one is STOICHIOMETRIES. In this set, A is the most frequent open letter (18 words). 2 words contain a doubled letter.

Full list 20

plainclothesmanplainclothesmenpraiseworthiestanticolonialismplainspokennessradiophotographsinistrodextralsociobiologicalsociobiologiststoxicologicallyantialcoholismsanticolonialistantimonopolistsantitheoreticalradiobiologicalradiobiologistsradioprotectionradioprotectivesemicolonialismstoichiometries

About this list

Words
20 (3 common words)
Common example
plainclothesman
Rare example
stoichiometries
Doubled letters
2
Ending in S
6
Most frequent letter
A (18)

Questions

How many 15-letter words matching ___i___o_______ are there?

20. 3 of them are common words.

What is a common example?

PLAINCLOTHESMAN is among the common words in this set.