Where does “allēno” come from?

allēno (Old Dutch) comes from Old Dutch al, from Proto-West Germanic all, from Proto-Germanic allaz, from Proto-Indo-European h₂él-.

Ancestry of “allēno”, step by step

Step	Language	Word	Meaning
1	Old Dutch	al	all, every; whole, entire; completely, wholly
2	Proto-West Germanic	all	all
3	Proto-Germanic	allaz	all
4	Proto-Indo-European	h₂él-	—

allēno — Etymology, Origin & Word History | Etymology Explorer