destabilisation vs British spelling

destabilisation and British spelling both are nouns.

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

destabilisation (noun)	British spelling (noun)
the action of destabilizing; making something less stable (especially of a government or country or economy)	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')