Where does “бережок” come from?

бережок (Russian) comes from Russian берёг, from Old East Slavic берегъ, from Proto-Slavic bergъ, from Proto-Balto-Slavic *bérgas, from Proto-Indo-European *bʰérǵʰos, from Proto-Indo-European bʰerǵʰ- — to rise; high, lofty; hill, mountain.

Ancestry of “бережок”, step by step

StepLanguageWordMeaning
1Russianберёгmasculine singular past indicative imperfective...
2Old East Slavicберегъbank; shore
3Proto-Slavicbergъhill; slope, cliff?; bank, shore?, coast?
4Proto-Balto-Slavic*bérgashill
5Proto-Indo-European*bʰérǵʰoshill
6Proto-Indo-Europeanbʰerǵʰ-to rise; high, lofty; hill, mountain
Every word from Proto-Indo-European bʰerǵʰ-Every word from Proto-Indo-European *bʰérǵʰosEvery word from Proto-Balto-Slavic *bérgas