Heiligabend (German) comes from German heilig, from German heilic, from Old High German heilag, from Proto-West Germanic hailag, from Proto-Germanic hailagaz, from Proto-Germanic hailaz, from Proto-Indo-European *kéh₂ilos — healthy.
Heiligabend (German): Christmas Eve (day before Christmas Day)
Definitions
Christmas Eve (day before Christmas Day)
Ancestry of “Heiligabend”, step by step
Heiligabend traces back through two separate lines of ancestry.