Where does “springæ” come from?

springæ (Old Danish) comes from Old Norse springa, from Proto-Germanic springaną, from Proto-Indo-European spr̥ǵʰ.

Ancestry of “springæ”, step by step

Step	Language	Word	Meaning
1	Old Norse	springa	—
2	Proto-Germanic	springaną	to spring, to jump up; to burst, to explode
3	Proto-Indo-European	spr̥ǵʰ	—

springæ — Etymology, Origin & Word History | Etymology Explorer