Where does “grobъ” come from?
grobъ (Proto-Slavic) comes from Proto-Slavic grěti, from Proto-Indo-European gʷʰer-, from Proto-Indo-European gʷʰe-gʷʰór-e ~ gʷʰe-gʷʰr-ḗr.
grobъ (Proto-Slavic): coarse, rude
Ancestry of “grobъ”, step by step
Words derived from “grobъ”