diagonalise vs British spelling

diagonalise is not a noun while British spelling is a noun.

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

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

diagonalise (verb)	British spelling (verb)
transform a matrix to a diagonal matrix