delusion Definition

1. The act of deluding or the state of being deluded.

Thesaurus: mistake, error, deception, misconception, fallacy, misapprehension.
2. psychol.
A false or mistaken belief, especially because of mental illness. Compare illusion, hallucination.
Thesaurus: illusion, hallucination, phantasm, mirage, fancy, misconception, misapprehension;