This dictionary has been compiled by authors who have been working in the fields of engineering geology, hydrogeology, and geocryology for many years. It includes terminology widely accepted in English and Russian literature devoted to the study of geoenvironmental problems and natural disasters. Moreover, the dictionary includes the terms from such adjacent fields as geophysics, physics of the atmosphere, oceanology, hydrology, soil science and soil mechanics, which are often used for describing geological processes and phenomena and assessing their effect on the environment. The dictionary includes more than 7,000 terms and expressions and reflects the widely accepted terminological base with respect to the geological environment. It is of particular interest to specialists engaged in the field of engineering geology and geoenvironmental sciences.