[de.lu.sion] n [ME, fr. LL delusion-, delusio, fr. deludere] (15c) 1 a: the act of deluding: the state of being deluded b: an abnormal mental state characterized by the occurrence of psychotic delusions
2. a: something that is falsely or delusively believed or propagated b: a persistent false psychotic belief regarding the self or persons or objects outside the self -- de.lu.sion.al adj -- de.lu.sion.ary adj