Where does “nyiss” come from?

nyiss (Hungarian) comes from Hungarian nyit, from Hungarian -t, from Proto-Uralic -tt.

Ancestry of “nyiss”, step by step

StepLanguageWordMeaning
1Hungariannyitto open
2Hungarian-tUsed to form the accusative case; -ed, -t. Used...
3Proto-Uralic-tt—
Every word from Proto-Uralic -tt →Every word from Hungarian -t →Every word from Hungarian nyit →