Entitlement is a guarantee of access to benefits because of rights, or by agreement through law. It also refers, in a more casual sense to someone's belief that he/she is deserving of some particular reward or benefit. It is often used as a pejorative term in popular parlance (i.e. a 'sense of entitlement').
In clinical psychology and psychiatry, an unrealistic, exaggerated, or rigidly held sense of entitlement may be considered a symptom of Narcissistic Personality Disorder.
In Land Development, the Entitlement Process is the legal method of obtaining approvals for the right to develop property for a desired use. (example: Re-zone)
In computer security, it can also refer to access control.