Where does “горішок” come from?

горішок (Ukrainian) comes from Ukrainian горіх, from Old East Slavic орѣхъ, from Proto-Slavic orěxъ, from Proto-Indo-European areyis-.

Ancestry of “горішок”, step by step

StepLanguageWordMeaning
1Ukrainianгоріхwalnut tree, especially common walnut; nut;...
2Old East Slavicорѣхъ—
3Proto-Slavicorěxъnut; walnut
4Proto-Indo-Europeanareyis-—
Every word from Proto-Indo-European areyis- →Every word from Proto-Slavic orěxъ →Every word from Old East Slavic орѣхъ →