delusion
/dɪˈluːʒən/Definitions
1. noun
a false or mistaken belief, especially one that is firmly maintained despite evidence to the contrary
“She suffered from a delusion that she was being followed everywhere she went.”
2. verb
to persuade (someone) to believe something that is false or mistaken
“The con artist tried to delude the investor into thinking that he was going to make a lot of money.”