Commonwealth of Australia vs Nullarbor Plain

Commonwealth of Australia and Nullarbor Plain both are nouns.

Word	Noun	Adjective	Verb	Adverb
Commonwealth of Australia	Yes	No	No	No
Nullarbor Plain	Yes	No	No	No

Commonwealth of Australia (noun)	Nullarbor Plain (noun)
a nation occupying the whole of the Australian continent; Aboriginal tribes are thought to have migrated from southeastern Asia 20,000 years ago; first Europeans were British convicts sent there as a penal colony	a vast arid plain of southern Australia stretching inland from the Great Australian Bight; has sparse vegetation and no surface water and is almost uninhabited; the site of a major rocket research center