\De*lu"sion\n. [L. delusio, fr. deludere. See
{Delude}.]
1. The act of deluding; deception; a misleading of the mind.
   --Pope.
2. The state of being deluded or misled.
3. That which is falsely or delusively believed or
   propagated; false belief; error in belief.
         And fondly mourned the dear delusion gone. --Prior.
Syn: {Delusion}, {Illusion}.
Usage: These words both imply some deception practiced upon
       the mind. Delusion is deception from want of
       knowledge; illusion is deception from morbid
       imagination. An illusion is a false show, a mere cheat
       on the fancy or senses. It is, in other words, some
       idea or image presented to the bodily or mental vision
       which does not exist in reality. A delusion is a false
       judgment, usually affecting the real concerns of life.
       Or, in other words, it is an erroneous view of
       something which exists indeed, but has by no means the
       qualities or attributes ascribed to it. Thus we speak
       of the illusions of fancy, the illusions of hope,
       illusive prospects, illusive appearances, etc. In like
       manner, we speak of the delusions of stockjobbing, the
       delusions of honorable men, delusive appearances in
       trade, of being deluded by a seeming excellence. ``A
       fanatic, either religious or political, is the subject
       of strong delusions; while the term illusion is
       applied solely to the visions of an uncontrolled
       imagination, the chimerical ideas of one blinded by
       hope, passion, or credulity, or lastly, to spectral
       and other ocular deceptions, to which the word
       delusion is never applied.'' --Whately.