What is the definition or description of: narcissistic personality disorder?

Narcissistic PD: Narcissistic personality d/o is a mental disorder with fixed and pervasive patterns of inner experience and outer behavior involving grandiosity, need for admiration, and lack of empathy for others. The person expects to be treated as superior, believes s/he is more special than others, and exploits others. Beneath all this lies a fragile self-esteem, vulnerable to the slightest criticism.

Serious disorder: The narcissist is hypothesized to have had parents that over valued them. Narcissists often over value themselves while devaluing others. They have limited psychological insight, difficulty with empathy, boundary issues, poor relationships, and hypersensitivity to insults because at a deeper level, their self-esteem is often fragile.

Narcissism: The hallmark of a narcissist is an immense ego, grandiosity, and self-importance, as well as being entitled, and a tendency to use and objectify others as well as thinking of people in all-good or all-bad terms instead of shades of gray. The core of a narcissist is profound insecurity.