illusion

(noun) an erroneous mental representation. Synonyms: semblance.

(noun) something many people believe that is false. Synonyms: fantasy, phantasy, fancy. Example: "They have the illusion that i am very wealthy."

(noun) the act of deluding; deception by creating illusory ideas. Synonyms: delusion, head game.

(noun) an illusory feat; considered magical by naive observers. Synonyms: magic trick, conjuring trick, trick, magic, legerdemain, conjuration, thaumaturgy, deception.