Thesaurus of Extension Education is a systematic and whole some compilation in the field of extension education consisting of large number of terms, concepts and ideas from various related disciplines of extension like agricultural extension, sociology, educational psychology, rural development, communication, training, information and communication technology, statistics, research methodology in social sciences, teaching-learning and program planning. It serves both as a ready reckoner and guide benefitting academics, professionals, students, researchers, teachers, extension personnel and field practitioners in agriculture. The authors fervently hope the book helps in achieving the objective for which it was intended.