This book provides easy to read, concise, and clinically useful explanations of over 1800 terms and concepts from the field of psychoanalysis. A history of each term is included in its definition and so is the name of its originator. The attempt is made to demonstrate how the meanings of the term under consideration might have changed, with new connotations accruing with the passage of time and with growth of knowledge. Where indicated and possible, the glossary includes diverse perspectives on a given idea and highlights how different analysts have used the same term for different purposes and with different theoretical aims in mind.