Master’s thesis is devoted to the complex description of the semantic-motivational field “Deceit” mainly on the material of Russian dialect lexis and phraseology. The work belongs to ethnolinguistics, that involves the reconstruction of a fragment of the Russian linguistic world picture, reflecting beliefs about deceit. The main methods by which the research is conducted are semantic, motivational and etymological analysis. In particular, the thesis includes defining the semantic components related to the concept of deceit (i.e. answering the questions “What do speakers mean by deceit?” and “What actions are represented in the language as deceptive?”), the field’s division on the semantic sectors, revealing links between the concept of deceit and other semantic areas (intelligence, speech, relations to work, etc.), founding narrow and cross-cutting motives of nominations, as well as basic nominative models used by the field; in addition, the etymological solutions are proposed for the number of motivationally “dark” items.