Where does “Кирилловна” come from?

Кирилловна (Russian) comes from Russian Кири́лл, from Ancient Greek Κύριλλος, from Ancient Greek κῡ́ριος — main; major; primary; principal.

Ancestry of “Кирилловна”, step by step

StepLanguageWordMeaning
1RussianКири́ллSaint Cyril apostle to the Slavs and inventor of the Glagolitic alphabet, which served as the basis for the Cyrillic alphabet
2Ancient GreekΚύριλλος
3Ancient Greekκῡ́ριοςmain; major; primary; principal
Every word from Ancient Greek κῡ́ριοςEvery word from Ancient Greek ΚύριλλοςEvery word from Russian Кири́лл