Where does “alt” come from?

alt (Faroese) comes from Old Norse allr, from Proto-Germanic allaz, from Proto-Indo-European h₂él-.

alt (Faroese): all

Definitions

Step	Language	Word	Meaning
1	Old Norse	allr	all, entire, whole; all, quite, entirely; gone,...
2	Proto-Germanic	allaz	all
3	Proto-Indo-European	h₂él-	—

alt — Etymology, Origin & Word History | Etymology Explorer