fiction vs phantasy

fiction and phantasy both are nouns.

Word	Noun	Adjective	Verb	Adverb
fiction	Yes	No	No	No
phantasy	Yes	No	No	No

As nouns, phantasy is a hyponym of fiction; that is, phantasy is a word with a more specific, narrower meaning than fiction:

fiction: a literary work based on the imagination and not necessarily on fact
phantasy: fiction with a large amount of imagination in it

Other hyponyms of fiction include dystopia, novel, fantasy, story, utopia.

fiction (noun)	phantasy (noun)
a literary work based on the imagination and not necessarily on fact	imagination unrestricted by reality
a deliberately false or improbable account	something many people believe that is false
	fiction with a large amount of imagination in it