limbo vs imaginary place

limbo and imaginary place both are nouns.

Word	Noun	Adjective	Verb	Adverb
limbo	Yes	No	No	No
imaginary place	Yes	No	No	No

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

limbo: (theology) in Roman Catholicism, the place of unbaptized but innocent or righteous souls (such as infants and virtuous individuals)
imaginary place: a place that exists only in imagination; a place said to exist in fictional or religious writings

Other hypernyms of limbo include fictitious place, mythical place.

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

limbo: an imaginary place for lost or neglected things
imaginary place: a place that exists only in imagination; a place said to exist in fictional or religious writings

Other hypernyms of limbo include fictitious place, mythical place.

limbo (noun)	imaginary place (noun)
(theology) in Roman Catholicism, the place of unbaptized but innocent or righteous souls (such as infants and virtuous individuals)	a place that exists only in imagination; a place said to exist in fictional or religious writings
an imaginary place for lost or neglected things
the state of being disregarded or forgotten