Book excerpt: First Published in 2015. This collection holds three volumes. Terrorism is a term that defies easy definition and its meaning has also changed over the course of history. Because this encyclopedia aims at comprehensiveness —across time, geography, and the conceptual landscape —it applies the broadest definition of terrorism: the use of violence or the threat of violence to effect political change through fear, in which the victims of the violence. The encyclopedia is divided into six parts.