brain tumour vs British spelling

brain tumour and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
brain tumour	Yes	No	No	No
British spelling	Yes	No	No	No

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