acclimatisation vs British spelling

acclimatisation and British spelling both are nouns.

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

acclimatisation (noun)	British spelling (noun)
adaptation to a new climate (a new temperature or altitude or environment)	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')