Where does “-ikkunainen” come from?

-ikkunainen (Finnish) comes from Finnish ikkuna, from Finnish akkuna, from Proto-Finnic *akkuna, from Old East Slavic окъно, from Proto-Slavic okъnò — window.

-ikkunainen (Finnish): windowed

Definitions

windowed

Ancestry of “-ikkunainen”, step by step

Step	Language	Word	Meaning
1	Finnish	ikkuna	window; sash
2	Finnish	akkuna	Alternative form of ikkuna
3	Proto-Finnic	*akkuna	window
4	Old East Slavic	окъно	window
5	Proto-Slavic	okъnò	window

Every word from Proto-Slavic okъnò →Every word from Old East Slavic окъно →Every word from Proto-Finnic *akkuna →