Where does “viidenkertainen” come from?

viidenkertainen (Finnish) comes from Finnish kertainen, from Finnish kerta, from Proto-Finnic kerta, from Proto-Indo-European kert-, from Proto-Turkic *keŕ- — to travel, tour.

Ancestry of “viidenkertainen”, step by step

viidenkertainen traces back through two separate lines of ancestry.

via Finnish kertainen

StepLanguageWordMeaning
1Finnishkertainentimes
2Finnishkertatime, occasion; time; times; also once, when the...
3Proto-Finnickertatime
4Proto-Indo-Europeankert-times; to weave, twist together; time
5Proto-Turkic*keŕ-to travel, tour

via Finnish viisi

StepLanguageWordMeaning
1Finnishviisifive
2Proto-Finnicviicifive
3Proto-Uralicwittefive; ten
Every word from Proto-Turkic *keŕ- →Every word from Proto-Indo-European kert- →Every word from Proto-Finnic kerta →