15-Letter Words Matching _O__S__________

There are 13 15-letter words that match _O__S__________. 2 are common words, such as FORESIGHTEDNESS and HOMOSEXUALITIES. A rarer one is POSTSTIMULATORY. In this set, I is the most frequent open letter (13 words). 6 words contain a doubled letter.

Full list 13

foresightednesshomosexualitiescoinstantaneousmonosaccharidespolysaccharidesionosphericallylongsightednessmonospecificitymonosyllabicitynonastronomicalnonpsychiatristpoststimulationpoststimulatory

About this list

Words
13 (2 common words)
Common example
foresightedness
Rare example
poststimulatory
Doubled letters
6
Ending in S
6
Most frequent letter
I (13)

Questions

How many 15-letter words matching _o__s__________ are there?

13. 2 of them are common words.

What is a common example?

FORESIGHTEDNESS is among the common words in this set.