muscle fibre vs Australian spelling

muscle fibre and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
muscle fibre	Yes	No	No	No
Australian spelling	Yes	No	No	No

muscle fibre (noun)	Australian spelling (noun)
an elongated contractile cell that forms the muscles of the body	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')