Where does “kopistella” come from?

kopistella (Finnish) comes from Finnish kopistaa, from Finnish taa, from Finnish taka, from Proto-Finnic taka, from Proto-Uralic taka — a place behind.

Ancestry of “kopistella”, step by step

Step	Language	Word	Meaning
1	Finnish	kopistaa	to tap to shake something off
2	Finnish	taa	Of movement, behind; a shorter form of taakse
3	Finnish	taka	the backside; In the expression "omasta takaa"...
4	Proto-Finnic	taka	back, a place behind
5	Proto-Uralic	taka	a place behind

Every word from Proto-Uralic taka →Every word from Proto-Finnic taka →Every word from Finnish taka →