7-Letter Words Matching ___UO__

There are 12 7-letter words that match ___UO__. 9 are common words, such as ARDUOUS and FATUOUS. A rarer one is TOLUOLS. In this set, S is the most frequent open letter (9 words). 0 words contain a doubled letter.

Full list 12

arduousfatuousliquorssequoiasinuoustenuousunquotevacuolevacuousnocuoustoluoletoluols

About this list

Words
12 (9 common words)
Common example
arduous
Rare example
toluols
Doubled letters
0
Ending in S
8
Most frequent letter
S (9)

Questions

How many 7-letter words matching ___uo__ are there?

12. 9 of them are common words.

What is a common example?

ARDUOUS is among the common words in this set.