Where does “bziák” come from?

bziák (Polish) comes from Polish beż, from Old Polish bez, from Proto-Slavic bъzъ, from Proto-Indo-European bʰeh₂ǵos — beech.

Ancestry of “bziák”, step by step

StepLanguageWordMeaning
1Polishbeżbeige
2Old Polishbezelder
3Proto-Slavicbъzъelderberry
4Proto-Indo-Europeanbʰeh₂ǵosbeech
Every word from Proto-Indo-European bʰeh₂ǵos →Every word from Proto-Slavic bъzъ →Every word from Old Polish bez →