operating theatre vs Australian spelling

operating theatre and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
operating theatre	Yes	No	No	No
Australian spelling	Yes	No	No	No

operating theatre (noun)	Australian spelling (noun)
a room in a hospital equipped for the performance of surgical operations	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')