Several attempts to classify karst terminology in an organized manner have been attempted in the past. The last few glossaries of karst terminology were organized in the late 1960s and published in the early 1970s. Since that time, many new terms related to karst in general have come into use throughout the world while other older karst terms are seldom used nowadays. In the mid 1990s the British Cave Research Association (BCRA) published and updated a dictionary that covers the general area of karst and caves, but did not focus on environmental issues. Many of the more recent karst terms are related to the upsurge in environmentalism and the recognition among karst cognoscenti that karst terranes are much more sensitive to man-induced effects on the environment than are other types of landscapes. In an attempt to be as broad as possible in this glossary, terms related to general hydrology and hydrogeology, common karst rock and mineral types, and many of the descriptive terms used in speleology even where they relate to specific localities, have been included. No attempt was made to exclude foreign karst terms although many are no doubt, missing. This has led to a much larger manuscript than was originally intended when this project was initiated, but it has provided for a more comprehensive document. Because many non-karst professionals, whether working on basic research or on environmental problems, need to have a general working knowledge of karst terminology, this glossary was developed to provide an up-to-date reference for more modern definitions of karst terms both currently in usage and now defunct.