Where does “arbitraarinen” come from?

arbitraarinen (Finnish) comes from French arbitraire, from Italian arbitrario, from Latin arbitrarius, from Latin -ārius, from Proto-Italic *-āzios — Forms relational adjectives to nouns (and rarely numerals).

Ancestry of “arbitraarinen”, step by step

arbitraarinen traces back through two separate lines of ancestry.

via French arbitraire

StepLanguageWordMeaning
1Frencharbitrairearbitrary
2Italianarbitrarioarbitrary
3Latinarbitrariusarbitrating; arbitrary
4Latin-āriuser
5Proto-Italic*-āziosForms relational adjectives to nouns (and rarely numerals)

via Finnish inen

StepLanguageWordMeaning
1Finnishinen
Every word from Proto-Italic *-āzios
arbitraarinen — Etymology, Origin & Word History | Etymology Explorer