Australian spelling vs muscle fibre

Australian spelling and muscle fibre both are nouns.

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

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