9-Letter Words Matching ____S__U_

There are 17 9-letter words that match ____S__U_. 6 are common words, such as ANTISERUM and COLOSTRUM. A rarer one is THRUSTFUL. In this set, T is the most frequent open letter (13 words). 5 words contain a doubled letter.

Full list 17

antiserumcolostrumdownspoutpotassiumreposefulstressfulendosteumequisetumunrestfulclaustrumcolosseummetestrusproestrusrainspoutregisseurrousseausthrustful

About this list

Words
17 (6 common words)
Common example
antiserum
Rare example
thrustful
Doubled letters
5
Ending in S
3
Most frequent letter
T (13)

Questions

How many 9-letter words matching ____s__u_ are there?

17. 6 of them are common words.

What is a common example?

ANTISERUM is among the common words in this set.