Devisserising 

Speaking untruths to such a degree that the speaker actually believes the untruths to be reality.

David says he is a genius to he's friends on a regular basis to the point they and he really believe that's a fact, but the actual fact is that David has a god complex and is mentally ill. When David is in the act of telling untruths he believes to be reality, he is actually Devisserising.

Devisserising by Andrew Hynson March 16, 2017

Devisverising 

Seeing things that aren't there, mirages being the product of devisverisation.

"I was sure it was my sister in that car, but it turns out I was just devisverising."

Devisverising by Sarah Black August 6, 2007