vitreous humour vs Australian spelling

vitreous humour and Australian spelling both are nouns.

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

vitreous humour (noun)	Australian spelling (noun)
the clear colorless transparent jelly that fills the posterior chamber of the eyeball	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')