Where does “дъно” come from?

дъно (Old East Slavic) comes from Proto-Slavic dъno, from Proto-Indo-European *dʰewb-.

Ancestry of “дъно”, step by step

StepLanguageWordMeaning
1Proto-Slavicdъnobottom
2Proto-Indo-European*dʰewb-

Words derived from “дъно

Every word from Proto-Indo-European *dʰewb-Every word from Proto-Slavic dъno