caesium vs Australian spelling

caesium and Australian spelling both are nouns.

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

caesium (noun)	Australian spelling (noun)
a soft silver-white ductile metallic element (liquid at normal temperatures); the most electropositive and alkaline metal	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')