13-Letter Words Matching ____O__S_____

There are 30 13-letter words that match ____O__S_____. 4 are common words, such as EFFLORESCENCE and IMPROVISATION. A rarer one is UNWHOLESOMELY. In this set, I is the most frequent open letter (25 words). 8 words contain a doubled letter.

Full list 30

Common words

efflorescenceimprovisationinflorescencevideocassetteaphrodisiacalaudiocassettefibrovascularimprovisatoryintromissionsmicrocosmicalneuromuscularneurovascular
efflorescenceimprovisationinflorescencevideocassetteaphrodisiacalaudiocassettefibrovascularimprovisatoryintromissionsmicrocosmicalneuromuscularneurovascularunpromisinglyantiobesitiescoprocessingsethnohistoricimprovisatoreimprovisatoriimprovisatorsmicrocassettemicrocosmosesmicrovascularnonhomosexualphotopositiveprotohistoricreprovisionedretrocessionssiphonostelestomboyishnessunwholesomely

About this list

Words
30 (4 common words)
Common example
efflorescence
Rare example
unwholesomely
Doubled letters
8
Ending in S
8
Most frequent letter
I (25)

Questions

How many 13-letter words matching ____o__s_____ are there?

30. 4 of them are common words.

What is a common example?

EFFLORESCENCE is among the common words in this set.