Cockaigne vs fictitious place

Cockaigne and fictitious place both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cockaigne	Yes	No	No	No
fictitious place	Yes	No	No	No

As nouns, fictitious place is a hypernym of Cockaigne; that is, fictitious place is a word with a broader meaning than Cockaigne:

Cockaigne: (Middle Ages) an imaginary land of luxury and idleness
fictitious place: a place that exists only in imagination; a place said to exist in fictional or religious writings

Other hypernyms of Cockaigne include imaginary place, mythical place.

Cockaigne (noun)	fictitious place (noun)
(Middle Ages) an imaginary land of luxury and idleness	a place that exists only in imagination; a place said to exist in fictional or religious writings