13-Letter Words Ending in UM

There are 16 13-letter words that end in UM. 2 are common words, such as CHRYSANTHEMUM and RUTHERFORDIUM. A rarer one is ODONTOGLOSSUM. In this set, I is the most frequent open letter (14 words). 5 words contain a doubled letter.

Full list 16

chrysanthemumrutherfordiumactinouraniumanticlinoriumferrochromiumhypochondriummycobacteriumperichondriumprotoactiniumsuccinctoriumtintinnabulumzoosporangiumarmamentariumdecamethoniumhexamethoniumodontoglossum

About this list

Words
16 (2 common words)
Common example
chrysanthemum
Rare example
odontoglossum
Doubled letters
5
Ending in S
0
Most frequent letter
I (14)

Questions

How many 13-letter words ending in um are there?

16. 2 of them are common words.

What is a common example?

CHRYSANTHEMUM is among the common words in this set.