Where does “suunpieksäjä” come from?

suunpieksäjä (Finnish) comes from Finnish pieksäjä, from Finnish pieksää, from Proto-Finnic peksädäk, from Proto-Uralic peksä- — to beat.

Ancestry of “suunpieksäjä”, step by step

suunpieksäjä traces back through two separate lines of ancestry.

via Finnish pieksäjä

StepLanguageWordMeaning
1Finnishpieksäjäthrasher one who thrashes or beats
2FinnishpieksääSynonym of piestä; Third-person singular...
3Proto-Finnicpeksädäkto beat
4Proto-Uralicpeksä-to beat

via Finnish suu

StepLanguageWordMeaning
1Finnishsuumouth
2Proto-Finnicsüüthread, fibre; annual ring; reason, cause
3Proto-Uralicśuwemouth
Every word from Proto-Uralic peksä-Every word from Proto-Finnic peksädäkEvery word from Finnish pieksää