British spelling vs mercerise

British spelling is a noun but mercerise is not a noun.

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

British spelling (noun)	mercerise (noun)
English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')

British spelling (verb)	mercerise (verb)
	treat to strengthen and improve the luster