Where does “гроб” come from?
гроб (Bulgarian) comes from Old Church Slavonic гробъ, from Proto-Slavic grǫbъ, from Proto-Slavic grěti, from Proto-Indo-European gʷʰer-, from Proto-Indo-European gʷʰe-gʷʰór-e ~ gʷʰe-gʷʰr-ḗr.
гроб (Bulgarian): grave
Ancestry of “гроб”, step by step