13-Letter Words Matching ______D___O__

There are 21 13-letter words that match ______D___O__. 10 are common words, such as COMMENDATIONS and CONTRADICTORY. A rarer one is THYROIDECTOMY. In this set, S is the most frequent open letter (18 words). 3 words contain a doubled letter.

Full list 21

commendationscontradictorydilapidationsfluoridationsgobbledegooksgobbledygooksintimidationsinvalidationsnonconductorspreconditionsadenoidectomychlamydosporejuglandaceousmastoidectomytransudationsautoxidationscontradictorsrefoundationsrevalidationssigmoidoscopythyroidectomy

About this list

Words
21 (10 common words)
Common example
commendations
Rare example
thyroidectomy
Doubled letters
3
Ending in S
15
Most frequent letter
S (18)

Questions

How many 13-letter words matching ______d___o__ are there?

21. 10 of them are common words.

What is a common example?

COMMENDATIONS is among the common words in this set.