13-Letter Words Matching ____O____N___

There are 54 13-letter words that match ____O____N___. 21 are common words, such as AIRWORTHINESS and ANALOGOUSNESS. A rarer one is TOMBOYISHNESS. In this set, I is the most frequent open letter (45 words). 25 words contain a doubled letter.

Full list 54

Common words

airworthinessanalogousnessconcomitantlycontortionistdissolutenesselaboratenessexplosivenessforeordainingfrivolousnessimprovidencesimprovidentlymicroorganism
airworthinessanalogousnessconcomitantlycontortionistdissolutenesselaboratenessexplosivenessforeordainingfrivolousnessimprovidencesimprovidentlymicroorganismpatronizinglypredominancespredominantlyproportionalsproportionateproportioningseaworthinesssorrowfulnesstemporarinessclamorousnesscompositenessconcomitancescorrosivenessdistortednessglamorousnessinviolatenessmicrobalancesneurosciencesnonporousnesspaleobotaniesprotoactiniumpurposivenessreproachinglysuffocatinglyunpromisinglyvisionarinessantiobscenitychemotaxonomyconfoundinglycorporealnesscustomarinesscyclohexanoneethnobotaniesethnobotanistethnosciencesmicrotechnicspaleobotanistpictorialnesspremoisteningpreportioningpromotivenesstomboyishness

About this list

Words
54 (21 common words)
Common example
airworthiness
Rare example
tomboyishness
Doubled letters
25
Ending in S
33
Most frequent letter
I (45)

Questions

How many 13-letter words matching ____o____n___ are there?

54. 21 of them are common words.

What is a common example?

AIRWORTHINESS is among the common words in this set.