Definition of delusion
1a : something that is falsely or delusively believed or propagated under the delusion that they will finish on schedule delusions of grandeur
b psychology : a persistent false psychotic belief regarding the self or persons or objects outside the self that is maintained despite indisputable evidence to the contrary
the delusion that someone was out to hurt him also : the abnormal state marked by such beliefs
2 : the act of tricking or deceiving someone : the state of being deluded … accused the Bohemian of having practised the most abominable arts of delusion among the younger brethren.— Walter Scott
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The first known use of delusion was in the 15th century
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