Australian spelling vs improvise

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

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

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

Australian spelling (verb)	improvise (verb)
	perform without preparation
	manage in a makeshift way; do with whatever is at hand