reorganisation vs reorganization

reorganisation and reorganization both are nouns.

Word	Noun	Adjective	Verb	Adverb
reorganisation	Yes	No	No	No
reorganization	Yes	No	No	No

As nouns, reorganisation and reorganization are synonyms defined as:

reorganisation and reorganization: the imposition of a new organization; organizing differently (often involving extensive and drastic changes)

Other synonyms of reorganisation include shake-up, shakeup.

reorganisation (noun)	reorganization (noun)
the imposition of a new organization; organizing differently (often involving extensive and drastic changes)	the imposition of a new organization; organizing differently (often involving extensive and drastic changes)
	an extensive alteration of the structure of a corporation or government