Where does “Amundsen” come from?

Amundsen (English) comes from Danish Amundsen, from Danish Amund, from Danish sen, from Old Norse seinn, from Proto-Germanic sainaz.

Ancestry of “Amundsen”, step by step

Step	Language	Word	Meaning
1	Danish	Amundsen	—
2	Danish	Amund	—
3	Danish	sen	late; belated, tardy; slow
4	Old Norse	seinn	late
5	Proto-Germanic	sainaz	—