A narcissist refers to an individual who exhibits narcissistic traits or has been diagnosed with Narcissistic Personality Disorder (NPD). Narcissistic Personality Disorder is a mental health condition characterized by a pervasive pattern of grandiosity, a constant need for admiration, and a lack of empathy for others. While many people may display some narcissistic traits, individuals with Narcissistic Personality Disorder exhibit these traits to an extent that significantly interferes with their relationships and functioning.