Where does “tonder” come from?

tonder (Dutch) comes from Middle Dutch tunder, from Old Dutch tundar, from Old Norse tundr, from Proto-Germanic tundrą — tinder.

tonder (Dutch): tinder

Definitions

Step	Language	Word	Meaning
1	Middle Dutch	tunder	—
2	Old Dutch	tundar	—
3	Old Norse	tundr	—
4	Proto-Germanic	tundrą	tinder

tonder — Etymology, Origin & Word History | Etymology Explorer