water vapour vs British spelling

water vapour and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
water vapour	Yes	No	No	No
British spelling	Yes	No	No	No

water vapour (noun)	British spelling (noun)
water in a vaporous form diffused in the atmosphere but below boiling temperature	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')