illusion

I

(New American Roget's College Thesaurus)

n. delusion, hallucination, vision, apparition; chimera, mirage, bubble, figment [of the mind or imagination]; dream, fool's paradise; misconception, self-delusion, error; legerdemain. See deception.

II

(Roget's IV) n.

1. [Unreal appearance]

Syn. fancy, hallucination, mirage, apparition, ghost, chimera, delusion, deception, fantasy, figment of the imagination, dream, vision, phantasm, image, trick of vision, optical illusion, myth, make-believe, déjà vu (French), paramnesia, castle in Spain, will-o'-the-wisp, ignis fatuus (Latin); see also dream 1 , fantasy 2 , vision 3 , 4 .

2. [Misconception]

Syn. delusion, confusion, false impression; see mistake 2 , misunderstanding 1 .

Syn.- illusion suggests the false perception or interpretation of something that has objective existence [ perspective in drawing gives the illusion of depth ] ; delusion implies belief in something that is contrary to fact or reality, resulting from deception, a misconception, or a mental disorder [ to have delusions of grandeur ] ; hallucination implies the apparent perception, in nervous or mental disorder, of something external that is actually not present; mirage refers to an optical illusion caused by atmospheric conditions, and, in figurative use, implies an unrealizable hope or aspiration

III

(Roget's 3 Superthesaurus) n.

apparition, mirage, hallucination, misconception, pipe dream, vision, phantasm, figment of the imagination, delusion, fallacy, deception.

IV

(Roget's Thesaurus II) noun 1. An erroneous perception of reality: delusion, hallucination, ignis fatuus, mirage, phantasm, phantasma, will-o'-the-wisp. See REAL. 2. An illusory mental image: daydream, dream, fancy, fantasy, fiction, figment, phantasm, phantasma, reverie, vision. See REAL. 3. A fantastic, impracticable plan or desire: bubble, castle in the air, chimera, dream, fantasy, pipe dream, rainbow. See REAL.