Delusion Law and Legal Definition

Delusion is a false unshakable belief contrary to fact. It involves a fixed belief that is either false, fanciful, or derived from deception. Delusion indicates an abnormality in the affected person's thought. The key feature of a delusion is the degree to which the person is convinced that the belief is true. A person with a delusion will hold firmly to the belief regardless of evidence to the contrary.