centralisation vs British spelling

centralisation and British spelling both are nouns.

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

centralisation (noun)	British spelling (noun)
the act of consolidating power under a central control	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')
gathering to a center