Australia
wiktionary
First attested 16th century, from Latin terra austrālis incōgnita(“unknown southern land”), from auster(“the south wind”). Used also in 1693 (quotation below). Popularised by Matthew Flinders in 1814 (quotation below).
Distantly cognate to Austria – same Proto-Indo-European root, but via German where it retained the earlier sense of “east” rather than “south”.
See also Terra Australis.
etymonline
Australia
from Latin Terra Australis (16c.), from australis "southern" + -ia. A hypothetical southern continent, known as terra australis incognita, had been proposed since 2c. Dutch explorers called the newfound continent New Holland; the current name was suggested 1814 by Matthew Flinders as an improvement over Terra Australis "as being more agreeable to the ear, and an assimilation to the name of the other great portions of the earth" ["Voyage to Terra Australis"]. In 1817 Gov. Lachlan Macquarie, having read Flinders' suggestion, began using it in official correspondence. The ultimate source is Latin auster "south wind," hence, "the south country" (see austral).
