Where does “nithe” come from?

nithe (Middle English) comes from Old English nīþ, from Proto-Germanic nīþą, from Proto-Indo-European neyH- — to lead.

Ancestry of “nithe”, step by step

Step	Language	Word	Meaning
1	Old English	nīþ	envy, hatred, malice, spite, jealousy; envy,...
2	Proto-Germanic	nīþą	hate, envy, malice
3	Proto-Indo-European	neyH-	to lead

nithe — Etymology, Origin & Word History | Etymology Explorer