The paper considers the problem of interdisciplinarity as the main tendency of today’s science to unite the methodology and terminology and adapt them to any academic field in order to achieve more objective results in the study of complex phenomena. This article is a descriptive one and it deals with problems of terms’ interpretations and their adaptation to the anthropocentric research viewed by scientists of different academic schools. The main idea of the article is to find the most relevant and systemic definition of the given terms, which could be used as a tool in further linguistic analysis applied to the coming research of the authors. Special attention is paid to the description of the Activity Theory from different aspects of its interpretation: psychological, sociological, linguistic; to the explanation of the correlation between the epistemic structure of knowledge and an open non-linear synergetic bilateral (conceptual and lexical-semantic) system influenced and motivated by processual factors to evolution in the modern discourse as the communicative activity of the interpreter and the constructor of discourse.