appearance vs illusion

appearance and illusion both are nouns.

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

As nouns, illusion is a hyponym of appearance; that is, illusion is a word with a more specific, narrower meaning than appearance:

Other hyponyms of appearance include semblance, 3-D, 3D, three-D, front.

appearance (noun)	illusion (noun)
the act of appearing in public view	the act of deluding; deception by creating illusory ideas
formal attendance (in court or at a hearing) of a party in an action	an illusory feat; considered magical by naive observers
pretending that something is the case in order to make a good impression	something many people believe that is false
outward or visible aspect of a person or thing	an erroneous mental representation
a mental representation
the event of coming into sight