Where does “Slavonia” come from?

Slavonia derives from Medieval Latin Sclavonia, from Latin Sclavus, from Byzantine Greek Σκλάβος, from Ancient Greek Σκλαβηνός.

Ancestry of “Slavonia”, step by step

Step	Language	Word	Meaning
1	Medieval Latin	Sclavonia	Slavonia
2	Latin	Sclavus	a Slav
3	Byzantine Greek	Σκλάβος	Slav
4	Proto-Slavic	slověninъ	Slav
5	Proto-Slavic	slovo	word
6	Proto-Balto-Slavic	ślawas	—
7	Proto-Indo-European	ḱléwos	fame
8	Proto-Indo-European	ḱlew-	to hear
9	Proto-Indo-European	ḱel-	to cover; to incline

Slavonia — Etymology, Origin & Word History | Etymology Explorer