fantasy vs conceive of

fantasy is a noun but conceive of is not a noun.

Word	Noun	Adjective	Verb	Adverb
fantasy	Yes	No	Yes	No
conceive of	No	No	Yes	No

As verbs, conceive of is a hypernym of fantasy; that is, conceive of is a word with a broader meaning than fantasy:

fantasy: indulge in fantasies
conceive of: form a mental image of something that is not present or that is not the case

Other hypernyms of fantasy include envisage, ideate, imagine.

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

fantasy (verb)	conceive of (verb)
indulge in fantasies	form a mental image of something that is not present or that is not the case