Where does “knøl” come from?

knøl (Norwegian Nynorsk) comes from Dutch knol, from Old English cnoll, from Proto-Germanic knudan-.

Ancestry of “knøl”, step by step

Step	Language	Word	Meaning
1	Dutch	knol	tuber; bulge, protrusion; nag, inferior horse
2	Old English	cnoll	summit
3	Proto-Germanic	knudan-	—

knøl — Etymology, Origin & Word History | Etymology Explorer