The dictionary contains definitions and interpretations of terms and concepts found in natural science texts. It covers the main historically established areas of empirical and theoretical sciences (physics, chemistry, biology, earth sciences, partially mathematics and "super-subject" system disciplines). In addition, the dictionary contains an interpretation of some polysemantic concepts of the methodology of science. Another feature of the dictionary is the accompaniment of some definitions with text illustrations and statements of famous scientists. The dictionary can be useful and interesting to all students of natural science, the history of science, disciplines related to ecology, and is primarily necessary for teachers, teachers, graduate students, students and inquisitive high school students.