heat of vaporisation vs British spelling

heat of vaporisation and British spelling both are nouns.

Word	Noun	Adjective	Verb	Adverb
heat of vaporisation	Yes	No	No	No
British spelling	Yes	No	No	No

heat of vaporisation (noun)	British spelling (noun)
heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature	English orthography used in the UK, Ireland and most of the Commonwealth (characterized by 'analyse', 'centre' and 'useable')