Where does “jommoinen” come from?

jommoinen (Finnish) comes from Finnish -möinen, from Finnish moinen, from Finnish -inen, from Finnish -uus, from Proto-Finnic -uc — -ness, -hood.

Ancestry of “jommoinen”, step by step

Step	Language	Word	Meaning
1	Finnish	-möinen	like
2	Finnish	moinen	such; -like
3	Finnish	-inen	-like, -ous, -y; -en; Creates adjectives from...
4	Finnish	-uus	Forms nouns from adjectives, expressing a quality
5	Proto-Finnic	-uc	-ness, -hood