Where does “grim” come from?

grim (Old Danish) comes from Old Norse grimmr, from Proto-Germanic grimmaz, from Proto-Indo-European gʰrem-, from Proto-Indo-European gʰer- — to rub; to stroke; to grind.

Ancestry of “grim”, step by step

Step	Language	Word	Meaning
1	Old Norse	grimmr	—
2	Proto-Germanic	grimmaz	grim, grimly, fierce
3	Proto-Indo-European	gʰrem-	to be angry; to sound, bellow, growl, roar, be...
4	Proto-Indo-European	gʰer-	to rub; to stroke; to grind

Words derived from “grim”

grim
grimhed

Every word from Proto-Indo-European gʰer- →Every word from Proto-Indo-European gʰrem- →Every word from Proto-Germanic grimmaz →