illusion vs deceit

illusion and deceit both are nouns.

Word	Noun	Adjective	Verb	Adverb
illusion	Yes	No	No	No
deceit	Yes	No	No	No

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

Other hypernyms of illusion include deception, dissembling, dissimulation.

illusion (noun)	deceit (noun)
the act of deluding; deception by creating illusory ideas	the act of deceiving
an illusory feat; considered magical by naive observers	the quality of being fraudulent
something many people believe that is false	a misleading falsehood
an erroneous mental representation