Semantic relations are at the core of any representational system, and are keys to enable the next generation of information processing systems with semantic and reasoning capabilities. Acquisition, description, and formalization of semantic relations are fundamentals in computer-based systems where natural language processing is required. Probing Semantic Relations provides a state of the art of current research trends in the area of knowledge extraction from text using linguistic patterns. First published as a Special Issue of Terminology 14:1 (2008), the current book emphasizes how definitional knowledge is conveyed by conceptual and semantic relations such as synonymy, causality, hypernymy (generic–specific), and meronymy (part–whole). Showing the difficulties and successes of pattern-based approaches, the book illustrates current and future challenges in knowledge acquisition from text. This book provides new perspectives to researchers and practitioners in terminology, knowledge engineering, natural language processing, and semantics.