Where does “sunder” come from?

sunder (Middle English) comes from Old English sundor-, from Old English sundor, from Proto-Germanic sundraz, from Proto-Indo-European snter-.

Ancestry of “sunder”, step by step

Step	Language	Word	Meaning
1	Old English	sundor-	apart, aloof, separately, in a manner that...
2	Old English	sundor	apart, separate, private, aloof, by one's self
3	Proto-Germanic	sundraz	separate, isolated, alone
4	Proto-Indo-European	snter-	—

sunder — Etymology, Origin & Word History | Etymology Explorer