Where does “kiintokuutio” come from?

kiintokuutio (Finnish) comes from Finnish kiinto-, from Finnish kiintää, from Finnish kiintyä, from Finnish -ua, from Proto-Finnic -üdäk — Forms mainly passive or anticausative verbs.

Ancestry of “kiintokuutio”, step by step

Step	Language	Word	Meaning
1	Finnish	kiinto-	solid, firm, fixed
2	Finnish	kiintää	to fasten, to keep attached or touching to...
3	Finnish	kiintyä	To become fond, attached
4	Finnish	-ua	Forms stative or inchoative intransitive verbs...
5	Proto-Finnic	-üdäk	Forms mainly passive or anticausative verbs

Every word from Proto-Finnic -üdäk →Every word from Finnish -ua →Every word from Finnish kiinto- →