Where does “hjon” come from?

hjon (Swedish) comes from Old Swedish hion, from Old Norse [[hjón]], [[hjún]], [[hjú]], from Proto-Germanic *hīwōnō.

Ancestry of “hjon”, step by step

Step	Language	Word	Meaning
1	Old Swedish	hion	—
2	Old Norse	[[hjón]], [[hjún]], [[hjú]]	—
3	Proto-Germanic	*hīwōnō	—

hjon — Etymology, Origin & Word History | Etymology Explorer