Australia, the country (Commonwealth of Australia) in the Southern Hemisphere; used to refer to the nation or matters related to it.
来年、仕事でオーストラリアに出張する予定だ。
I'm scheduled to go on a business trip to Australia next year.
オーストラリアの自然は多様で美しい。
Australia's nature is diverse and beautiful.
彼女はオーストラリア出身で、英語が母語だ。
She is from Australia and English is her native language.