Where does “grandis” come from?

grandis (Proto-Balto-Slavic) comes from Proto-Indo-European gʷʰrondʰ-i-s, from Proto-Indo-European gʷʰrendʰ- — to crush; gnash.

Ancestry of “grandis”, step by step

Step	Language	Word	Meaning
1	Proto-Indo-European	gʷʰrondʰ-i-s	—
2	Proto-Indo-European	gʷʰrendʰ-	to crush; gnash

grandis — Etymology, Origin & Word History | Etymology Explorer