Where does “andæ” come from?

andæ (Old Danish) comes from Old Norse andi, from Proto-Germanic anadô, from Proto-Indo-European h₂enh₁‑.

Ancestry of “andæ”, step by step

Step	Language	Word	Meaning
1	Old Norse	andi	breath; aspiration; spirit, soul 1871, C.R....
2	Proto-Germanic	anadô	breath; spirit; zeal
3	Proto-Indo-European	h₂enh₁‑	—

andæ — Etymology, Origin & Word History | Etymology Explorer