tyrannise vs British spelling

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

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

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

tyrannise (verb)	British spelling (verb)
rule or exercise power over (somebody) in a cruel and autocratic manner
rule a country as a tyrant