Australian spelling vs overemphasise

Australian spelling is a noun but overemphasise is not a noun.

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

Australian spelling (noun)	overemphasise (noun)
English orthography used in Australia (characterized by 'analyse', 'centre', 'usable')

Australian spelling (verb)	overemphasise (verb)
	place special or excessive emphasis on