Where does “krookkia” come from?

krookkia (Ingrian) comes from Ingrian -ia, from Proto-Finnic -idak, from Proto-Uralic -j-.

Ancestry of “krookkia”, step by step

StepLanguageWordMeaning
1Ingrian-iaUsed to form continuative verbs from other verbs
2Proto-Finnic-idakapplicative suffix
3Proto-Uralic-j-—
Every word from Proto-Uralic -j- →Every word from Proto-Finnic -idak →Every word from Ingrian -ia →