Where does “Katainen” come from?

Katainen (Finnish) comes from Finnish kataja, from Proto-Finnic kataga, from Proto-Finno-Ugric koča.

Ancestry of “Katainen”, step by step

StepLanguageWordMeaning
1Finnishkatajajuniper; common juniper, "Juniperus communis"
2Proto-Finnickatagajuniper
3Proto-Finno-Ugrickoča—
Every word from Proto-Finno-Ugric koča →Every word from Proto-Finnic kataga →Every word from Finnish kataja →