This book offers an unrivalled introduction to key concepts and debates within the field of Critical Terrorism Studies. Comprising 160 original entries, the book introduces readers to important events such as 9/11, organisations such as Al-Qaeda, theories such as feminism, methods such as discourse analysis, and debates such as new terrorism, and the impact these have had on research in this area. Each entry is accompanied by suggestions for further reading, helping readers to develop their understanding. The book includes a new full-length introduction to Critical Terrorism Studies, setting out how the field has evolved. The dictionary's accessible and engaging style makes it an essential resource for anyone interested in thinking critically around terrorism, counterterrorism and political violence.