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