15-Letter Words Matching _________S_N___

There are 12 15-letter words that match _________S_N___. 5 are common words, such as DEFENSELESSNESS and MEANINGLESSNESS. A rarer one is EXHAUSTLESSNESS. In this set, E is the most frequent open letter (12 words). 12 words contain a doubled letter.

Full list 12

defenselessnessmeaninglessnessreconnaissancesremorselessnessthoughtlessnessmeasurelessnessoverrepresentedpassionlessnesspurposelessnessstandoffishnessemotionlessnessexhaustlessness

About this list

Words
12 (5 common words)
Common example
defenselessness
Rare example
exhaustlessness
Doubled letters
12
Ending in S
11
Most frequent letter
E (12)

Questions

How many 15-letter words matching _________s_n___ are there?

12. 5 of them are common words.

What is a common example?

DEFENSELESSNESS is among the common words in this set.