Where does “-ono-” come from?

-ono- (Proto-Indo-European) comes from Proto-Indo-European -o-mno-, from Proto-Indo-European -o-meno- — adverbial suffix of neuter gender.

Ancestry of “-ono-”, step by step

StepLanguageWordMeaning
1Proto-Indo-European-o-mno-—
2Proto-Indo-European-o-meno-adverbial suffix of neuter gender
Every word from Proto-Indo-European -o-meno- →Every word from Proto-Indo-European -o-mno- →