Definition of Illusion:

false appearance; false belief

Synonyms of Illusion:

semblance, deception, myth, confusion, image, delusion, fantasy, misconception, hallucination, pipe dream, ghost, rainbow, bubble, apparition, mockery, fancy, invention, chimera, misapprehension, error, mirage, make-believe, daydream, phantasm, trip, hocus-pocus, fallacy, false impression, head trip, optical illusion, seeming, virtual reality, paramnesia, figment of imagination, idolism, ignus fatuus, misbelief, misimpression, , déja vu

Opposite/Antonyms of Illusion:

event, right, correction, certainty, being, fact, truth, reality

Sentence/Example of Illusion: