Where does “Рождество” come from?

Рождество (Russian) comes from Proto-Slavic roďьstvo, from Proto-Slavic roditi, from Proto-Slavic rodъ, from Proto-Balto-Slavic radás, from Proto-Indo-European wréh₂ds — root.

Ancestry of “Рождество”, step by step

Step	Language	Word	Meaning
1	Proto-Slavic	roďьstvo
2	Proto-Slavic	roditi	to give birth, to bear; to bear; to care about,...
3	Proto-Slavic	rodъ	genus, race, birth; kin, family, tribe, clan;...
4	Proto-Balto-Slavic	radás	birth, genus
5	Proto-Indo-European	wréh₂ds	root

Every word from Proto-Indo-European wréh₂ds →

Рождество — Etymology, Origin & Word History | Etymology Explorer