13-Letter Words Matching O__________S_

There are 21 13-letter words that match O__________S_. 10 are common words, such as OBJECTIVENESS and OBLIVIOUSNESS. A rarer one is OVERSWEETNESS. In this set, N is the most frequent open letter (19 words). 18 words contain a doubled letter.

Full list 21

objectivenessobliviousnessobnoxiousnessobsessivenessobtrusivenessoffensivenessoffhandednessofficiousnessornithologistoutspokennessoccasionalismopportunenessoverhastinessobstinatenessonomatologistoperativenessoppositionistoveradvertiseovereagernessoverembellishoversweetness

About this list

Words
21 (10 common words)
Common example
objectiveness
Rare example
oversweetness
Doubled letters
18
Ending in S
15
Most frequent letter
N (19)

Questions

How many 13-letter words matching o__________s_ are there?

21. 10 of them are common words.

What is a common example?

OBJECTIVENESS is among the common words in this set.