fantasise vs fantasy

fantasise is not a noun while fantasy is a noun.

Word	Noun	Adjective	Verb	Adverb
fantasise	No	No	Yes	No
fantasy	Yes	No	Yes	No

As verbs, fantasise and fantasy are synonyms defined as:

Other synonyms of fantasise include fantasize.

fantasise (noun)	fantasy (noun)
	imagination unrestricted by reality
	something many people believe that is false
	fiction with a large amount of imagination in it

fantasise (verb)	fantasy (verb)
indulge in fantasies	indulge in fantasies
portray in the mind