aqueous humour vs Australian spelling

aqueous humour and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
aqueous humour	Yes	No	No	No
Australian spelling	Yes	No	No	No

aqueous humour (noun)	Australian spelling (noun)
the limpid fluid within the eyeball between the cornea and the lens	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')