fantasy world vs phantasy

fantasy world and phantasy both are nouns.

Word	Noun	Adjective	Verb	Adverb
fantasy world	Yes	No	No	No
phantasy	Yes	No	No	No

As nouns, phantasy is a hypernym of fantasy world; that is, phantasy is a word with a broader meaning than fantasy world:

fantasy world: something existing solely in the imagination (but often mistaken for reality)
phantasy: imagination unrestricted by reality

Other hypernyms of fantasy world include fantasy.

fantasy world (noun)	phantasy (noun)
something existing solely in the imagination (but often mistaken for reality)	imagination unrestricted by reality
	something many people believe that is false
	fiction with a large amount of imagination in it