<P> The name Australia (pronounced (əˈstɹæɪljə, - liə) in Australian English) is derived from the Latin Terra Australis ("southern land"), a name used for a hypothetical continent in the Southern Hemisphere since ancient times . When Europeans first began visiting and mapping Australia in the 17th century, the name Terra Australis was naturally applied to the new territories . </P> <P> Until the early 19th century, Australia was best known as "New Holland", a name first applied by the Dutch explorer Abel Tasman in 1644 (as Nieuw - Holland) and subsequently anglicised . Terra Australis still saw occasional usage, such as in scientific texts . The name Australia was popularised by the explorer Matthew Flinders, who said it was "more agreeable to the ear, and an assimilation to the names of the other great portions of the earth". The first time that Australia appears to have been officially used was in April 1817, in which Governor Lachlan Macquarie acknowledged the receipt of Flinders' charts of Australia from Lord Bathurst . In December 1817, Macquarie recommended to the Colonial Office that it be formally adopted . In 1824, the Admiralty agreed that the continent should be known officially by that name . The first official published use of the new name came with the 1830 publication of "The Australia Directory" by the Hydrographic Office . </P> <P> Colloquial names for Australia include "Oz" and "the Land Down Under" (usually shortened to just "Down Under"). Other epithets include "the Great Southern Land", "the Lucky Country", "the Sunburnt Country", and "the Wide Brown Land". The latter two both derive from Dorothea Mackellar's 1908 poem "My Country". </P> <P> Human habitation of the Australian continent is estimated to have begun around 65,000 to 70,000 years ago, possibly with the migration of people by land bridges and short sea - crossings from what is now Southeast Asia . These first inhabitants may have been ancestors of modern Indigenous Australians . At the time of European settlement in the late 18th century, most Indigenous Australians were hunter - gatherers with complex economies and societies . Indigenous Australians have an oral culture with spiritual values based on reverence for the land and a belief in the Dreamtime . The Torres Strait Islanders, ethnically Melanesian, were originally horticulturists and hunter - gatherers . The northern coasts and waters of Australia were visited sporadically by fishermen from Maritime Southeast Asia . </P>

Which country us also known as down under