overutilisation vs Australian spelling

overutilisation and Australian spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
overutilisation	Yes	No	No	No
Australian spelling	Yes	No	No	No

overutilisation (noun)	Australian spelling (noun)
exploitation to the point of diminishing returns	English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')