With entries ranging from Alzheimer's disease to the Zeignarik effect, this unique dictionary provides information about the researchers, scholars, and scientists whose names have become part of terms in common use among psychologists. Over 800 eponyms of current or historical interest are presented, together with full definitions and a short biography of the person whose name is appended to the term. In addition to terms originating in psychology itself, there are entries from statistics, physiology, psychiatry, neurology, linguistics, and artificial intelligence that have found their way into psychological parlance.