Where does “-o-” come from?

-o- (Swedish) comes from Old Swedish -u, from Old Norse -u.

-o- (Swedish): interfix

Definitions

interfix

Ancestry of “-o-”, step by step

Step	Language	Word	Meaning
1	Old Swedish	-u	—
2	Old Norse	-u	—

Words derived from “-o-”

Every word from Old Norse -u →

-o- — Etymology, Origin & Word History | Etymology Explorer