Where does “Австралия” come from?

Австралия (Bashkir) comes from Russian Австра́лия, from English Australia, from Latin terra austrālis incōgnita, from Latin auster, from Proto-Italic *austeros.

Ancestry of “Австралия”, step by step

Step	Language	Word	Meaning
1	Russian	Австра́лия	Australia
2	English	Australia	—
3	Latin	terra austrālis incōgnita	—
4	Latin	auster	The south wind; south
5	Proto-Italic	*austeros	—

Every word from Proto-Italic *austeros →

Австралия — Etymology, Origin & Word History | Etymology Explorer