demineralisation vs British spelling

demineralisation and British spelling both are nouns.

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

demineralisation (noun)	British spelling (noun)
the removal of minerals and mineral salts from a liquid (especially from water)	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')
abnormal loss of mineral salts (especially from bone)