immunisation vs British spelling

immunisation and British spelling both are nouns.

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

immunisation (noun)	British spelling (noun)
the act of making immune (especially by inoculation)	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')