Where does “välilehti” come from?

välilehti (Finnish) comes from Finnish väli-, from Finnish väli, from Proto-Finnic välji.

välilehti (Finnish): tab

Definitions

Step	Language	Word	Meaning
1	Finnish	väli-	mid-, middle-, intermediate, inter-
2	Finnish	väli	gap, space; interval; distance
3	Proto-Finnic	välji	—

välilehti — Etymology, Origin & Word History | Etymology Explorer