wishful thinking vs illusion

wishful thinking and illusion both are nouns.

Word	Noun	Adjective	Verb	Adverb
wishful thinking	Yes	No	No	No
illusion	Yes	No	No	No

As nouns, illusion is a hypernym of wishful thinking; that is, illusion is a word with a broader meaning than wishful thinking:

Other hypernyms of wishful thinking include fancy, fantasy, phantasy.

wishful thinking (noun)	illusion (noun)
the illusion that what you wish for is actually true	the act of deluding; deception by creating illusory ideas
	an illusory feat; considered magical by naive observers
	something many people believe that is false
	an erroneous mental representation