Illusion is a term used to describe an unreal or deceptive APPEARANCE, sound, or experience. DELUSION (8 letters) is a false belief or opinion held in spite of evidence to the contrary. APPARITION (10 letters) is a ghostly figure or an unexpected sight. DECEIT (6 letters) is an act of deliberately misleading someone. IMAGINATION (11 letters) is the ability to form mental images and ideas. APPEARANCE (10 letters) is the way something looks or seems. MISAPPREHENSION (15 letters) is a misunderstanding or misinterpretation of something. DAYDREAM (8 letters) is a pleasant or wishful FANTASY. ERROR (5 letters) is a mistake or inaccuracy. GHOST (5 letters) is an APPARITION of a dead person. DECEPTION (9 letters) is the act of deceiving or misleading someone. RAINBOW (7 letters) is an arch of colors in the sky caused by refraction of sunlight. BUBBLE (6 letters) is a thin sphere of liquid filled with air or gas. FACADE (6 letters) is an outward APPEARANCE that is maintained to conceal a less pleasant reality. MIRAGE (6 letters) is an OPTICAL illusion caused by atmospheric conditions. OPTICAL (7 letters) is relating to sight or vision. EIDOLON (7 letters) is an imaginary or idealized figure. FANTASY (7 letters) is an imaginative idea or DAYDREAM. PHANTASM (8 letters) is an illusion or APPARITION. Magictrick (10 letters) is an entertainment involving sleight of hand and DECEPTION. Smokeandmirrors (15 letters) is a metaphor for DECEPTION or evasion.