myriametre vs Australian spelling

myriametre and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
myriametre	Yes	No	No	No
Australian spelling	Yes	No	No	No

myriametre (noun)	Australian spelling (noun)
a metric unit of length equal to 10,000 meters	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')