Where does “tændæ” come from?

tændæ (Old Danish) comes from Old Norse tenda, from Proto-Germanic tandijaną, from Proto-Germanic tinnaną, from Proto-Indo-European dendʰneti.

Ancestry of “tændæ”, step by step

Step	Language	Word	Meaning
1	Old Norse	tenda	—
2	Proto-Germanic	tandijaną	to kindle, to light on fire
3	Proto-Germanic	tinnaną	to burn
4	Proto-Indo-European	dendʰneti	—

tændæ — Etymology, Origin & Word History | Etymology Explorer