The article deals with the phenomenon of enantiosemy based on the dialect vocabulary. One of the reasons for enantiosemy is the ability for polar evaluation of one and the same phenomenon, finding out the opposite signs of the same notion or the object of reality. The varieties of meanings of one polysemantic word lead to development of opposite sememes, as a rule, based on hyperbolic intensive display of both positive and negative features. The research of Don folk geographic terms revealed a big number of enantionyms.

There is considered the role of nouns of the Ukrainian origins in the formation of the vocabulary system of Don dialects. Close geographical position and long contacts between Don Cossacks and the Ukrainians couldn’t but favour complicated linguistic processes which resulted in formation of the unique lexical system with the equal role of the words of the general East Slavic origins and the lexical units that appeared in the dialects in the period after differentiation of the Russian and Ukrainian languages.

There is considered the role of local geographic terms in forming the language world picture. There is proved that the images of the highest and the lowest points of landscape and their nominations form the basis of dialect speakers world view, and particular features of natural environment promote the development of more detailed meanings in general geographic terms and the transformation of commonly used non-term nominations into geographic appellatives.