12-Letter Words Matching ________M_U_

There are 20 12-letter words that match ________M_U_. 3 are common words, such as CUMULONIMBUS and PRASEODYMIUM. A rarer one is TRICHOTOMOUS. 0 words contain a doubled letter.

Full list 20

cumulonimbuspraseodymiumpseudonymouscryptonymousectothermousepithalamiumheteronomousheteronymoushomochromousmonospermouspachydermousphysostomouspolychromousprothalamiumsuperpremiumcryptogamouseurythermousheterogamousnonunanimoustrichotomous

About this list

Words
20 (3 common words)
Common example
cumulonimbus
Rare example
trichotomous
Doubled letters
0
Ending in S
16

Questions

How many 12-letter words matching ________m_u_ are there?

20. 3 of them are common words.

What is a common example?

CUMULONIMBUS is among the common words in this set.