polymerisation vs British spelling

polymerisation and British spelling both are nouns.

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

polymerisation (noun)	British spelling (noun)
a chemical process that combines several monomers to form a polymer or polymeric compound	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')