Where does “дев'ятий” come from?
дев'ятий (Ukrainian) comes from Proto-Slavic devętъ, from Proto-Balto-Slavic dewin(t)as, from Proto-Balto-Slavic newin(t)as, from Proto-Indo-European h₁néwn̥ — nine.
дев'ятий (Ukrainian): ninth
Ancestry of “дев'ятий”, step by step