Where does “Dîmboiu” come from?

Dîmboiu (Romanian) comes from Romanian Dîmbu, from Romanian dâmb, from Hungarian domb, from Old Polish dąb, from Proto-Slavic dǫbъ, from Proto-Indo-European dʰanw-.

Ancestry of “Dîmboiu”, step by step

Step	Language	Word	Meaning
1	Romanian	Dîmbu	—
2	Romanian	dâmb	knoll
3	Hungarian	domb	hill, mound, hump
4	Old Polish	dąb	—
5	Proto-Slavic	dǫbъ	oak tree; oak
6	Proto-Indo-European	dʰanw-	—

Every word from Proto-Indo-European dʰanw- →Every word from Proto-Slavic dǫbъ →Every word from Old Polish dąb →