azbuka

From Slavic languages, especially using the Cyrillic script, compare Russian а́збука (ázbuka) (also Belarusian, Bulgarian, Macedonian, Serbo-Croatian, Ukrainian), from the first Old Church Slavonic letter names аз (az) and буки (búki) (compare Ancient Greek ἀλφάβητος (alphábētos) = ἄλφα (álpha) + βῆτα (bêta) or Persian الف (alef) + باء (bâ')), from Proto-Slavic *(j)azъ, *buky.

来源：wiktionary