Amber Alert. A system by which the police can rapidly broadcast to the general public a report of a missing or endangered child by means of radio and television announcements. • The alert is named for Amber Hagerman of Texas, a nine-year-old who was abducted and murdered in 1996 by an unknown person. The system has been adopted by many communities in the U.S. and Canada. Local variations exist. In Arkansas, for example, the system is called the Morgan Nick Alert after a child who was abducted by a stranger in 1995. — Also termed Amber Plan.