Where does “астрологиня” come from?

астрологиня (Ukrainian) comes from Ukrainian -и́ня, from Proto-Slavic -yni, from Proto-Slavic -ni — one.

Ancestry of “астрологиня”, step by step

StepLanguageWordMeaning
1Ukrainian-и́няforms feminine equivalents of masculine animate nouns
2Proto-Slavic-yniDenominal, forming feminine noun forms....
3Proto-Slavic-nione
Every word from Proto-Slavic -ni →Every word from Proto-Slavic -yni →Every word from Ukrainian -и́ня →