Definition of Illusion

Noun: illusion i'loo-zhun

An erroneous mental representation
- semblance
Something that many people believe but is false
"they have the illusion that I am very wealthy";
- fantasy, phantasy [archaic], fancy
The act of deluding; deception by creating illusory ideas
- delusion, head game
An illusory feat; considered magical by naive observers
- magic trick, conjuring trick, trick, magic, legerdemain, conjuration, thaumaturgy, deception