British spelling vs lacklustre

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

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

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

British spelling (adjective)	lacklustre (adjective)
	lacking luster or shine
	lacking brilliance or vitality