British spelling vs de-emphasise

British spelling is a noun but de-emphasise is not a noun.

Word	Noun	Adjective	Verb	Adverb
British spelling	Yes	No	No	No
de-emphasise	No	No	Yes	No

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

British spelling (verb)	de-emphasise (verb)
	reduce the emphasis