Where does “Itäsalmi” come from?

Itäsalmi (Finnish) comes from Finnish Salmi, from Finnish -lä, from Finnish -as, from Proto-Finnic -s, from Proto-Finno-Ugric -s.

Ancestry of “Itäsalmi”, step by step

Itäsalmi traces back through two separate lines of ancestry.

via Finnish Salmi

StepLanguageWordMeaning
1FinnishSalmiA town in Russian Karelia
2Finnish-läFront vowel variant of -la
3Finnish-asForms some adjectives; Forms some nouns
4Proto-Finnic-sForms nouns
5Proto-Finno-Ugric-s—

via Finnish itä

StepLanguageWordMeaning
1Finnishitäeast; east, eastern; East, the Orient
2Proto-Finnicitäeast
3Proto-Uralicitä-to appear
Every word from Proto-Finno-Ugric -s →Every word from Finnish -lä →Every word from Finnish -as →