Open English Wordnet
Nouns
(n)illusion, semblancean erroneous mental representation“Artists use perspective in art to create an illusion of depth.” (n)illusion, fantasy, phantasy, fancysomething many people believe that is false“they have the illusion that I am very wealthy”,
“He fancies himself to be a local celebrity.” (n)delusion, illusion, head gamethe act of deluding; deception by creating illusory ideas“She has a delusion that she is being spied on.”