Webster's English Dictionarydelusion
de.lu.sion \di-'lu:-zh*n\ \-'lu:zh-n*l, -'lu:-zh*n-*l\ n [ME, fr. L delusion-, delusio, fr. delusus pp. of deludere] 1a: the act of deluding : the state of being deluded 1b: an abnormal mental state characterized by occurrence of delusions 2a: something that is falsely or delusively believed or propagated 2b: a false belief regarding the self or persons or objects outside the sel f that persists despite the facts and is common in some psychotic statesan something accepted as true or real that is actually false or unreal. DELUSION implies self-deception concerning facts or situations and usu. a disordered state of mind; ILLUSION implies an ascription of truth or reality to something that seems to normal perception to be true or real but in fact is not; HALLUCINATION implies an image that has no physical basis but is the result of disordered nerves or mental derangement; MIRAGE, literally an optical illusion presented to normal vision, suggests by extension a goal that is unattainable because it exists only in dreams or hopes - de.lu.sion.al aj SYN syn DELUSION, ILLUSION, HALLUCINATION, MIRAGE me