(Internationally used term, originally the German form of the Slavic word kras or krs, meaning a bleak waterless place; it is the German name for a district east of Trieste having such terrane.) A terrane, generally underlain by limestone or dolomite, in which the topography is chiefly formed by the dissolving of rock, and which may be characterized by sinkholes, sinking streams, closed depressions, subterranean drainage, and caves . The term karst unites specific morphological and hydrological features in soluble (mostly carbonate) rocks. Morphological features include karren, dolinas (sinkholes), jamas, ponors, uvalas, poljes, caves, caverns, etc. Hydrological features include basins of closed drainage, lost rivers, estavelles, vauclusian springs, submarine springs, more or less individualized underground streams and incongruity of surface and underground divides. Karst is understood to be the result of natural processes in and on the earth's crust cause by solution and leaching of limestones, dolomites, gypsum, halite, and other soluble rocks . Synonyms: (French.) karst; (German.) Karst; (Greek.) karst; (Italian.) carso, carsismo; (Russian.) karst; (Spanish.) karst; (Turkish.) karst; (Yugoslavian.) krs, kras. See also buried karst; cone karst; covered karst; exhumed karst; Halbkugelkarst; Holokarst; Kegelkarst; Merokarst; microkarst; naked karst; paleokarst; pseudokarst; relict karst; Spitzkegelkarst; subjacent karst; syngenetic karst; thermokarst; tower karst.