Where does “hevoskaakki” come from?

hevoskaakki (Finnish) comes from Finnish hevonen, from Proto-Finnic hepoinen, from Proto-Finnic -inen — -ish, -ic, -like, -y; -en.

Ancestry of “hevoskaakki”, step by step

hevoskaakki traces back through two separate lines of ancestry.

via Finnish hevonen

StepLanguageWordMeaning
1Finnishhevonenhorse, "Equus caballus"; horse; knight
2Proto-Finnichepoinenhorse
3Proto-Finnic-inen-ish, -ic, -like, -y; -en

via Finnish kaakki

StepLanguageWordMeaning
1Finnishkaakkinag old useless horse
Every word from Proto-Finnic -inen →Every word from Proto-Finnic hepoinen →Every word from Finnish hevonen →