Where does “некуда” come from?

некуда (Russian) comes from Russian не, from Proto-Slavic ne, from Proto-Balto-Slavic nē, from Proto-Indo-European né — not; no.

Ancestry of “некуда”, step by step

некуда traces back through two separate lines of ancestry.

via Russian не

StepLanguageWordMeaning
1Russianнеnot, no, -n't, without; Idiomatic negative usage;...
2Proto-Slavicnenot
3Proto-Balto-Slavicnēnot
4Proto-Indo-Europeannénot; no

via Russian куда́

StepLanguageWordMeaning
1Russianкуда́(to) where?
2Old East Slavicкѫдаwhere, whither
3Proto-Slavickǫdawhere, whither
4Proto-Indo-Europeankʷom-dʰ-—
Every word from Proto-Indo-European né →Every word from Proto-Balto-Slavic nē →Every word from Proto-Slavic ne →