Australian spelling vs square millimetre

Australian spelling and square millimetre both are nouns.

Word	Noun	Adjective	Verb	Adverb
Australian spelling	Yes	No	No	No
square millimetre	Yes	No	No	No

Australian spelling (noun)	square millimetre (noun)
English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')	a unit of area measurement equivalent to 1 millimeter in length multiplied by 1 millimeter in width.