agonising vs British spelling

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

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

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

agonising (adjective)	British spelling (adjective)
extremely painful