Where does “rooku” come from?

rooku (Ingrian) comes from Proto-Finnic rooko, from Proto-Finnic rooka, from Proto-Germanic rōkō — care, attention.

Ancestry of “rooku”, step by step

StepLanguageWordMeaning
1Proto-Finnicrookoreed
2Proto-Finnicrookafood; meal
3Proto-Germanicrōkōcare, attention

Words derived from “rooku”

Every word from Proto-Germanic rōkō →Every word from Proto-Finnic rooka →Every word from Proto-Finnic rooko →
rooku — Etymology, Origin & Word History | Etymology Explorer