Where does “*hasal” come from?

*hasal (Old Dutch) comes from Old Norse hasl, from Proto-Germanic *haslaz, from Proto-Celtic koslos, from Proto-Indo-European koselos — hazel.

Ancestry of “*hasal”, step by step

Step	Language	Word	Meaning
1	Old Norse	hasl	—
2	Proto-Germanic	*haslaz	—
3	Proto-Celtic	koslos	hazel
4	Proto-Indo-European	koselos	hazel

*hasal — Etymology, Origin & Word History | Etymology Explorer