Where does “rinnakkaisesti” come from?

rinnakkaisesti (Finnish) comes from Finnish rinnakkainen, from Finnish rinnakkain, from Finnish -kkäin, from Finnish -käs, from Proto-Finnic -k'as, from Proto-Finnic -s, from Proto-Finno-Ugric -s.

Ancestry of “rinnakkaisesti”, step by step

StepLanguageWordMeaning
1Finnishrinnakkainenparallel
2Finnishrinnakkainside by side; in parallel; superlative degree of...
3Finnish-kkäinFront vowel variant of -kkain
4Finnish-käsFront vowel variant of -kas
5Proto-Finnic-k'asForms adjectives from nouns, indicating a...
6Proto-Finnic-sForms nouns
7Proto-Finno-Ugric-s
Every word from Proto-Finno-Ugric -sEvery word from Finnish -käsEvery word from Proto-Finnic -s