: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
:something that is falsely or delusively believed or propagated
- under the delusion that they will finish on schedule
: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 abnormal state marked by such beliefs
- the delusion that someone was out to hurt him