British spelling vs optimise

British spelling is a noun but optimise is not a noun.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
optimise	No	No	Yes	No

British spelling (noun)	optimise (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')

British spelling (verb)	optimise (verb)
	act as an optimist and take a sunny view of the world
	make optimal; get the most out of; use best
	modify to achieve maximum efficiency in storage capacity or time or cost